Plan to frame part of basement and have a few questions

Submitted by Ad-Nauseam91 t3_z82h4d in DIY

Hey all - as the title says i'm planning on embarking on some DIY framing of part of my unfinished basement as i'm moving my small workshop into the basement. Scouring the interwebs has left me with more questions than answers and hoping some folks with real life experience doing this can help shine some light on my questions.

Some quick background, i live in New England (so i have big temperature swings throughout year if that matters) and my house was build in 1985 (heard that could matter for sealed foundation or not?). I have never had water in the basement and did the test with the sheet of plastic and all looks dry.

  1. I see conflicting information on framing the exterior walls of the basement. Some show studs set off the wall and a sheet of material stapled to backside to let air flow, and i see others attach foamboard insulation directly to foundation then use strips of wood to drywall too... the airflow makes sense to me, but i'm an amateur, are their pros and cons of going directly onto the foundation vs. leaving a gap?
  2. I'm planning on only framing out half the basement, are their risks of not doing the interior wall portion (outside of dust, etc.). I was thinking of just doing the 3 outer edges half way through the basement, then not put the divider wall up so its easier to get to the other side of basement.
  3. After deciding the framing technique, can i just leave the bare concrete floor or do i need to vapor barrier/floor it? Since its just a woodshop i don't mind the concrete floor but not sure if that creates any unintended imbalances.

Thanks to anyone who read this lengthy post!

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strongmans t1_iy9ubxx wrote

Use High Density Foam attached to the concrete walls and tape the seams. This is your vapor barrier. Now stud a wall up as normal with sill gasket on the bottom of the wall to prevent the wood from touching the concrete. You can insulate the 2x4 walls as well but do not add another vapor barrier (plastic).

The floor is fine as is.

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preferablyprefab t1_iy9ygli wrote

This is the correct answer for this climate zone.

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lolmeansilaughed t1_iybonum wrote

Do you have any links as to the correct vapor barrier for each climate zone in the US? Like OP, I've never been able to find good info on that either.

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preferablyprefab t1_iye5x74 wrote

No, it’s not really prescriptive. There are so many variables of construction methods and materials, heating and cooling systems, and how they interact.

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lolmeansilaughed t1_iyet79d wrote

Thanks, I figured as much.

My house is in Maryland where we get all four seasons, with a walkout-style foundation and a natural stone facade, built in the early 60s. I did some remodeling and got inside some walls above and below grade and found no vapor barrier. At the time I couldn't find good info so just assumed it was built correctly, and the vapor barrier was either part of the exterior or was not needed. Homes under construction around here you always see with Tyvek Homewrap before the siding goes on, which is assume is a vapor barrier.

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preferablyprefab t1_iyf2bja wrote

Tyvek is a water resistant barrier - its purpose is to reduce wetting behind your siding (whatever it is) and it is slightly vapour open to allow moisture to escape if the wall assembly does get wet. Think of it a bit like gore-tex; water doesn’t get in but some vapour can get out. Buildings are ok getting a bit wet - it’s generally only bad if they can’t dry out.

Tyvek can also perform as an air barrier if detailed correctly but that’s not what you’re seeing on most residential construction.

Older buildings don’t usually have a vapour barrier and it’s not an issue because they are also poorly insulated and draughty. So they tend to dry out.

In a better insulated house that’s relatively air tight, problems occur where warm air meets a colder surface and you get condensation. Could be warm outside air meeting cold interior surface if you have AC. Could be warm interior air meeting cold exterior surface if you have heat blasting on cold days. If that condensed moisture gets trapped and won’t dry out, you get rot.

So - your 60 year old house that’s rot free is probably fine, but may be an energy pig. If you update it with better insulation and make it air tight to lower energy costs, that’s when you need some advice to get the details right.

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more_than_just_ok t1_iyaky3n wrote

This is correct method. Foamboard directly on the concrete leaves no room for convection. In winter the top of the basement wall will be cold and the bottom buried part will be warmer. You do not want warm air moving and coming into contact with the cold and condensing the water out. In an unfinished basement this isn't a problem because enough heat is being lost through the wall that the dew point is somewhere in the wall, but once you insulate inside, the inside of the concrete will become colder.

u/strongmans suggestion to frame a proper 2x4 wall, not just use furring strips, is also a good one, because then you have a proper wall to hang stuff on in your shop and you have room for electrical boxes on the exterior walls.

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Ad-Nauseam91 OP t1_iyav3nv wrote

Thank you and u/strongmans follow up question around the different temps in foundation higher up than lower. If I were to frame, insulate and drywall the walls, but leave the floor as is, that doesn’t create any weird effect? What if I leave the ceiling as is too (not sure I’d do that but curious if that changes anything)

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ComDet t1_iyb1ajv wrote

I would also recommend doing epoxy floor, and treated wood at least for the bottom plate.

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more_than_just_ok t1_iyb4qhw wrote

Epoxy floor would look nice. I said I would do it on my floor 10 years ago, but it hasn't happened yet. You can do treated wood for the bottom plate in each wall, the other option, u/strongmans mentioned it, is sill gasket, basically 3.5 inch wide closed-cell foam, about 1/8" thick that comes in a roll that you put between the bottom plate and the floor. It's also used between the top of the foundation and the sill plate (or anywhere wood touches concrete) in most newer houses.

If you're building just a few walls yourself, spend the extra money and use 2.5 or 3 inch deck screws instead of nails (Robertson #2 head if you can get them in New England?) Very useful when you mess up and need to redo stuff, and you can hold the board with one hand, the drill in the other while the drill bit holds the screw in place.

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nightwing2000 t1_iybav2m wrote

I thought Robertson (the square hole screw heads) was more of a Canada thing?

Yes, my go to reference for construction, Holmes on Homes, says NEVER have bare untreated wood touching cement. It can absorb water from the cement.

You also have to consider the risk of basement leakage. Cracked foundation wall leaking, or rain/melt water buildup leaking in, may damage the bottom of your walls. Is this a risk? How good is the foundation drainage? Would you notice?

And, in much older houses, the concrete basement floor may not be particularly level. A raised wood subfloor allows you to level things so you can use tiles or carpet. But you may have a central floor drain, you may never notice if there's a water seepage until mold shows up, etc. Basement floods do more damage if you have to replace a raised floor. (I saw a Holmes episode where he used a floor leveler compound, like a very wet cement that leveled like water but hardened - to get rid of excessive slope. Don't block the drain. )

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Mego1989 t1_iyblhsf wrote

Self leveling underlayment/cement. It's neat stuff! Very messy and expensive though

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Doctor_Frasier_Crane t1_iycmpz5 wrote

I used 12-inch wide 6-mil poly under my basement walls and wrapped it up both sides and stapled it in place. Provides separation from the floor and some minor flood protection. I can get up to 6 inches of water on the floor and still have some protection for the studs.

I also have rolled dimple flooring underlay to provide separation and airflow under the vinyl plank flooring.

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Dire88 t1_iybaqxg wrote

Technically, you can skip PT on the bottom and sill plates if using sill guard. But the cost savings for non-PT aren't worth it imo.

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strongmans t1_iychzmi wrote

You'll be fine. It's when you close in the walls preventing air movement is why you need a vapor barrier. I've done this method tons of times and never an issue. If it's going to be a shop why bother finishing the floor. Unless you want to spend the money and epoxy it for looks.

You can use PT for the sill plate if you want but it's going way overboard. The sill gaskets breaks the capillary movement of moisture. You shouldn't use PT lumber inside but it's not the end of the world.

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more_than_just_ok t1_iyb2s8v wrote

You can leave the floor as is, especially for a workshop, and leave the ceiling unfinished too. My basement is 70% fully finished (drywall ceiling, carpet) but I've left the laundry/utility room and a storage room with no ceiling and a concrete floor.

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JohnC53 t1_iybynw2 wrote

All the exposed joist space makes for a ton of additional storage if you get creative. Another bonus of leaving the ceiling unfinished.

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nightwing2000 t1_iyb8cyc wrote

Exactly - why would you want air movement behind the interior walls? All it does is guarantee that if there's one cold spot, instead it makes the whole area behind the insulation a cold spot. Especially the ground level cold will migrate to the basement floor level, spreading the love. Insulation flat against the walls makes sure any cold does not spread beyond where it's cold through the wall.

In Canada, where winters are probably colder at times, the standard now is 2x6 exterior. Or... for basements, a sheet of styrofoam insulation, then insulated 2x4. If you plan to put weight on the walls as others mention, with cupboards, shelving, or tool pegboards- you want the strength of 2x4 on standard 16-inch centers.

The vapour barrier should be on the hot side of the insulation, so inside humidity in winter does not migrate inside the walls to condense. Usually for pink fiberglas insulation, this is plastic sheet on top of the wall, stapled to the studs. Typically, it's "glued" using acoustic sealant so the holes from the stapes are sealed. Electrical outlets 9and cable TV, network, etc.) are on the warm side of the plastic, using tape to seal the wire coming through the plastic. the key is NO AIRHOLES.

(Alternative construction is sprayed in expanding foam, which is then sawed flat level with the studs when it hardens. Since it's sprayed as a liquid and forms a continuous piece, a vapor barrier is unnecessary, it's already airtight.)

Take pictures as you do the work, especially of the walls before sealed from view. Not sure where you are, but here you can do electrical yourself if (a) you know what you are doing and (b) with the supervision of a qualified electrician. (I.e. he/she says "yes, that's up to code".)

Some municipalities require a building permit, especially if you touch electrical or plumbing. I has a relative in the USA, when she sold her house 20 years later, someone somewhere went through the house's building permit history (house inspector?) and claimed the family room behind the garage was never issued a permit to be finished. AFAIK she bought it finished. Then bought and remortgaged when she bought the half it from her (ex)husband, with no hassles. I sold my house in Canada with no such hassles. How persnickety is your municipality?

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Dire88 t1_iybbshw wrote

I had to demo 36ft of basement wall due to a water damage issue, and was set on doing it properly with 2in XPS while maintaining the existing wall thickness due to existing clearances.

Ended up going with 2x3 studs mounted flat on the XPS foam. To account for deflection if loads are added to the wall, I slapped two 5in tapcons through each stud.

Run electric through the joists and down between studs. Can add additional 1in insulation if desired.

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jam1324 t1_iyajyr2 wrote

This is how we do it around here, lot of hacks don't but this is the best way. Believe you need at least 2 inches of foam to count as a vapour barrier, or exceed what would put the dew point in your wall, at least thats what inspectors want around here. Just speak to your local building agency and see what they require before you do anything.

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Boysterload t1_iyb75gy wrote

For a basement, would it make sense to frame with metal studs instead of wood? I'd probably use a pressure treated stud for the base.

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more_than_just_ok t1_iybvxdb wrote

I've never gotten a straight answer on this question. Steel studs can rust, wood studs can rot. Pressure treated can rust your nails or screws if you're not careful. When I redid my basement, I found 40 year wood that was good as new, but I live in a high elevation cold/dry climate.

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Mego1989 t1_iybkjtm wrote

I didn't know sill gasket was a thing! I just built a wall in my basement and I used PT for the sill, and shimmed it off the floor cause I do get leaks sometimes.

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SJHillman t1_iycowfz wrote

>You can insulate the 2x4 walls as well

This was required for where I am when using less than 4 inches of foam due to the required R-value, which imo is dumb as hell. But if you're getting it inspected, worth checking the insulation codes as many places now require a separate insulation inspection.

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Cmdr_Toucon t1_iydi551 wrote

I had read somewhere along the line to glue the foam using vertical glue runs instead of horizontal. Idea was any moisture could run down to floor instead of getting trapped. Is this needed or just overthinking?

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ronlester t1_iyaj1xe wrote

One more thought if you are worried about moisture - don’t finish with regular sheetrock, use greenboard (water resistant)

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imoutohere t1_iy9muxr wrote

You are going to many different opinions. I’ll start, I use 2x4s for the wall with at least a 1” gap between the back of the stud and the masonry. That way you will have air flow and the insulation won’t rest against the concrete. I would paint the floor if it’s a shop.

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windy496 t1_iya7fiw wrote

Air flow? From where to where?

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imoutohere t1_iycvv7j wrote

Okay air space? A gap? Void? Chose one. The point is you don’t want fiberglass insulation touching the concrete.

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windy496 t1_iydk71b wrote

Why?

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imoutohere t1_iydknt9 wrote

It's not recommended that you apply fiberglass insulation directly to a concrete wall. If you must use fiberglass, there needs to be a space between the insulation and the wall. If not, the place where the insulation touches the concrete will be overtaken by mold and mildew.

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Ad-Nauseam91 OP t1_iy9nfa1 wrote

Thanks for starting it off! Do you do a vapor type wrap on the back side of the studs to help hold in the insulation?

In regards to painting floor, what’s the purpose? Looks? Or also ceiling moisture?

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Professional-Buy579 t1_iyasgsd wrote

I live in MN and here they give us 2 choices: 1) frame the wall 1" from the concrete. Put a vapor barrier on the concrete side and slice a small " smile" in the vapor barrier on the concrete side. Insulate the framing and then put a real vapor barrier on the room side and drywall it. The " smile" allows any vapor that infiltrates the insulation to evaporate. The concrete side barrier allows a gap between the framing and the concrete so that any moisture evaporates from there. 2) frame the wall 0.5 to 1" in front the concrete and spray foam it at least 2" thick. Both vapor barrier and insulation. I got this info from the inspector when I finished my basement. I did the first way. Spray foam is nice but too expensive

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goss_bractor t1_iya629f wrote

You could vapour wrap it, or just run string that's stapled, or use 3mm ply, stainless steel cable, garbage bags, there's tons of options. Wrap will be the easiest though.

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fangelo2 t1_iyaod1i wrote

This is the way I’ve always done it. I don’t like anything attached directly to basement walls. This way has several advantages. First of all by using 2x4 studs ( wood or metal) you have an easy way to run electrical wiring. You can use relatively inexpensive regular insulation. You can position the wall to cover pipes, ducts, or anything else ( install access panels for clean outs etc. ) No chance if mold forming.

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Scooter_127 t1_iy9s4ne wrote

My advice is to check local code. Where I live a permit is required to finish a basement.

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papajestify t1_iy9tadr wrote

Is there a place to go to for definitive local code? I’m in CO. Any clarification on that is appreciated!

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_Soter_ t1_iyal8r0 wrote

CO will vary between different city/counties. Start at the website for your city or county and you should be able to find permit requirements and building codes.

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asad137 t1_iyanp2v wrote

check library.municode.com for your municipality.

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Emergency-Wave-5335 t1_iybggny wrote

If you're within city limits, the city is the Authority Having Jurisdiction. If you're not within the city limits, the county is the Authority Having Jurisdiction.

If you live with a city that doesn't do zoning or permitting, they will direct you to the county.

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beforewhom t1_iy9pn06 wrote

Question a. Are big temp swings happening dynamically in 1 week or statically over weeks or months? Temp swings primarily mean drastic changes in humidity, while expansion and contraction happens it's primary going to come into play when in the same week or over a span of weeks you have huge swings of humidity, for example Houston in the fall/spring where between 1 week you have humidtiy of 70%, 20%, 30%, 90%, and 10%. If they happen slowly across seasons you may not need to factor in as you are.

1.Concrete can carry moisture and you don't want this moisture to go into your wood studs especially during humid seasons or wet/rainy/monsoon seasons. You can circumvent this by getting treated 2x4s, 1x4 or whatever size wood you decide to frame with. Otherwise you can do literally any of the options you described, pink boards, vapor barrier, or offset from wall so only bottom piece needs to be treated wood. You could also put the 2x4 on a vapor barrier on the ground and then you wouldnt need any treated wood.

  1. It sounds like you are saying (i'm deciding randomly) that your north, east and south walls are outer facing and your western wall isn't and so you want to only frame these three. No risks to doing this. Insulation is used (framing and drywall included) are done to prevent sound, temp, and motion transfer. in your situation you would be insulating from sound and temp since these aren't load bearing walls. You would do this wear you want to prevent sound and temp from transferring for any reason.

  2. No reason to vapor the floor except as mentioned above. If you have lived in the house for a while and are pretty sure there aren't water issues in the basement then no real reason to do beyond what you already did, which is a moisture test. That being said your primary concern having a woodshop should be airflow out of your woodshop unless you don't like breathing clean air. You should plan this and install this before you put your walls up and you might want to add a section of framing to accomodate hanging this. Look up Air Filtration systems on Rockler or any other major woodworking website and spec one out based on the cubic footage of your workshop. After this air filtration system you might need to add an outdoor whole similar to a dryer vent or such that will introduce a water failure point. I say do this early to insure all sealing is done completely correct and you can observe this. A dryer vent isn't anything new or crazy but a new hole in the wall is something you want to make sure is done right.

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Ad-Nauseam91 OP t1_iy9qdao wrote

Thanks for the extensive response… I’m probably being too anxious about moisture, just rather play it safe I suppose.

Sounds like either option I’m probably good with which is a positive.

Lastly, I already have a 1.5hp dust collector that I’m transitioning to 2 stage, so it does a pretty good job at dust collection. And has a 1 micron filter. I still plan to get one of those ceiling hanging air filters too though, can never be too cautious on air quality!

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beforewhom t1_iy9ta38 wrote

Dust collector collects visible dust. Always protect your lungs by constantly filtering the air. Air Filtration cannot be understated especially in stagnant environments like a basement. This becomes even more important if your furnace/register is in the basement.

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StraightUpBullfrog t1_iy9zwf4 wrote

Agreed, from what I've read, the sub 1-micron is the worst for you health-wise, and as mentioned here, invisible to the naked eye. The more filtration/air changes, the better. May be worth looking into grabbing a Dylos or equivalent air quality monitor to make sure whatever measures you're putting in place are actually working the way you think they are. I believe mine measures down to 0.3um?....a couple hundred bucks invested in having healthy lungs in the future is a bargain in my world. Also a big fan of cyclone + venting the DC outside but I understand that isn't always possible.

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Ad-Nauseam91 OP t1_iyax9dl wrote

I could probably vent it out through the small windows in my basement, that’s how my dryer vent is setup today already.

How is DC vented outside? Like how I plan to set mine up, hoses to tools, that go through cyclone then into the filter canister with bag attached to that. Does the venting happen after the canister filter? Sorry newb question but having trouble picturing it.

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nightwing2000 t1_iybcnrp wrote

If it's an old house with good concrete foundation walls and good drainage, and hasn't leaked yet, you should be safe.

Another point - be sure that the basement wall vapour barrier plastic is sealed to the insulation's vapour barrier in between the joists against the exterior wall. (back in the 50's or before, vapour barriers were an occasional concept, usually that paper-backed fiber insulation was the vapour barrier. Proper insulation was also often just a suggestion.)

Also, by code - while pink fiberglas insulation can be exposed (with a plastic vapour barrier) - Styrofoam insulation must be covered with drywall; otherwise, a fire could burn the Styrofoam to produce noxious fumes. Sealing it behind drywall limits this risk. Also, know your code - electrical outlets in a finished room must be no less than 12 feet apart (since many appliances have 6 foot cords) not counting doors and windows. My local code allows for zero outlets in unfinished areas. (i.e. no drywall).

And... finishing a basement (or part) can add to your tax bill if the municipality gets wind of it.

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Pristine-Today-3079 t1_iyb0jex wrote

Have you done some radon testing lately? Might be a good idea so that you don't need to incorporate remediation later.

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ronlester t1_iyaj2yx wrote

One more thought if you are worried about moisture - don’t finish with regular sheetrock, use greenboard (water resistant)

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drodver t1_iy9qnqa wrote

You won’t prevent moisture coming through the foundation so don’t trap it with plastic or the like. I would do a gap and use unfaced insulation for the exterior walls

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ILikeLeadPaint t1_iyaqqd4 wrote

If the walls are dry (and no efflorescence), r 7.5 foam board right to the concrete, and mineral wool between your studs.

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abadonn t1_iyarct4 wrote

Check out a product called InSoFast, I used it in my basement remodel and liked it a lot. It is insulation and framing combined, goes together like Legos.

It also has a corrugated back face that still allows the concrete to breathe.

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Emergency-Wave-5335 t1_iybh3pu wrote

My stupid brain read

>It also has a corrugated black face that still allows the concrete to breathe.

["Wait, brain. That doesn't make sense. Read it again..."]

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Mountain-Ad-3321 t1_iyarh7b wrote

Just did mine:

2” XPS glued to walls 1” XPS on slab with double layer 7/16 CDX plywood. Concrete screws on first layer and wood for second 48” opening to mechanical room with barn sliders

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Mountain-Ad-3321 t1_iyasupc wrote

Just did mine:

Check your local code so you don’t get screwed and you have resale value. Added egress window since one room was bedroom 2” XPS glued to walls 1” XPS on slab with double layer overlapping 7/16 CDX plywood. XPS will act as thermal and vapor barrier Concrete screws on first layer of floor ply and wood for second. Floor allowed 2x4 construction without wood on concrete. Use a laser square since basement walls are not square. Snap an offset chaulk line and find your min gap. That’s your 2x4 wall offset Closed off mechanical room since AC and boiler make a lot of noise 48” opening to mechanical room with barn sliders for access Rockwool insulation Fire block the wall top plate I added a heat loop off boiler but in the end I didn’t need it. Room stays 72 in winter

Do it right for the long run

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Mildly_Angry_Biscuit t1_iyba5ss wrote

Lot of good advice - I agree with the foam board, then wall, but the one thing I would do prior to putting the foam board up is to seal any cracks on the concrete wall with hydraulic cement then put a couple of good coats of drylok paint to help seal the wall. You've never had water in the basement, but you don't want to find out you have an issue behind your framed out wall and foam. - where you'll likely find the first sign of a problem is a large patch of mold.
If you're leaving part of the basement unfinished, I'd also recommend keeping a dehumidifier going in that space to help keep the humidity level at a consistently low-to-moderate level.

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l397flake t1_iyavl7y wrote

How often will you be using this shop? What will you be doing in the shop? Any kind of continuous partial flame, etc. I like to keep things simple. Iam in CA. So keep that in mind. 1 2x6 walls, 1 “ away from masonry 6” insulation in the framed wall. If any kind of flame use , use 5/8” type x Sheetrock in the ceiling. I might freeze standing on a concrete floor, so consider a plywood floor on treated sleepers which would be glued onto the floor, no anchors. Plenty of receptacles don’t forget 220 v in case of the type of equipment. Keep it simple it will work out. Good luck and enjoy your hobbies

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Ad-Nauseam91 OP t1_iyaw3g9 wrote

Appreciate the response, just some woodworking is all, table saw, sanding, planing, etc. electrical will be big, and dust collection.

Trying not to overthink it but I want to do it once right! Floor I’m curious on, I’m going back and forth on that one.

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l397flake t1_iyax9h6 wrote

As you can see, safety is always a consideration. I always found that important for my clients. I am a retired GC 50 year continuous operations, but in Southern Cal. Good luck

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Raul_McCai t1_iyawfew wrote

  1. leave the gap you already know why

  2. dust well you already know about it so you answered your own question

  3. Concrete makes tons of dust. I wish I sealed my concrete first.

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ntyperteasy t1_iyb6ias wrote

The temperature of that bare concrete floor will be pretty cold in the winter (45 F? maybe). If you intend to heat the space, doing something to reduce heat losses there will save money in the long run. And, a little insulation there will reduce the heating bills in the rest of the house, as it is probably a major source of heat loss if the bottom of the first floor isn't finished. If the bottom of the first floor is fully insulated, then the heat loss to the rest of the house is a minor issue.

You can use a "subfloor panel" which is osb with a plastic spacer to stand it off the concrete, or build your own with some high density foam, pressure treated sleepers, and a plywood floor.

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JNDCLLC t1_iybbwxz wrote

Follow the advise I’ve seen here and use mold resistant drywall too.

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piledriveryatyas t1_iybfbhd wrote

The answers you've gotten are not "wrong", but they may not be right either. If you research code throughout the country you'll find that it varies significantly by region. Two areas that specifically can and will vary (there may be more); the requirement to build a floating wall in basements, and insulation.

No walls that you erect in a basement will be load bearing, but if your home and area are subject to soil settling or heaving, you'll want to make sure they don't become load bearing by being pushed up into the joists. That's what floating walls are designed to prevent.

Insulation is different depending on to climate zone and local code. The one thing that a few folks pointed out is to make sure you don't put 2 vapor barriers in (accidentally or on purpose) as this will trap moisture and cause mold.

You didn't say where you live (or I missed it if you did) but if your basement came with an insulation blanket already on the wall, you can actually frame up to that. If it didn't, how cold it gets will determine how much insulation and what kind of framing you want to use.

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Ad-Nauseam91 OP t1_iyco6u6 wrote

Definitly going to check with my building dept before starting, talking with some folks in town it sounds like they won’t care since it won’t be 100% finished but I want to check anyways.

I live in New England, CT to be exact, maybe I forgot to put that in the original post.

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Lastexit25 t1_iybh960 wrote

I finished half my basement a year ago, I also live in new England. I bought 5 gallons of drylok first and put two coats on the wall and floor. Then put 2in foam boards against the wall and use tape in between each foam board. I framed right that right after. I just had to be mindful of leaving enough space for plumbers to access any drain pipes, so I had to make an adjustment on one corner. I've had no issues with water at all since completing it and it stays pretty warm in the winter even without the baseboards on.

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diito t1_iybm0gi wrote

I am in Michigan where everyone has a basement and they are commonly finished. I did one myself:

I framed my walls 1" off the walls with a pressure treated bottom plate and installed fiberglass insulation with no vapor barrier. You do NOT want a vapor barrier, you want the walls to breath. A vapor barrier will trap water behind it and cause mold. With the insulation being off the wall it will not get wet or damp so no worries. If I was to do it over again I'd use rock wool insulation instead as that doesn't mold if it gets wet. That said in the 10 years I lived in that house after finishing the basement I never had any issues and no musty smells etc that you commonly encounter with incorrectly done basements.

Even if your basement is dry now it will eventually get wet. You need to do everything you can now to prevent it. It happened to me, I had a spot the carpet got very wet 10 feet into the room during a heavy rain. Basements of that era, 70s-80s, it's common for the tie rods to rust out over time and water to leak in via the rod holes. Mine were not leaking when I finished the basement. To fix it I pulled the carpet and pad up and dried it all out with box fans right away. The pad was anti microbial and the carpet nylon so it dried very fast but I continued to run the fans for several days to be sure. To fix the rod holes I took a section of drywall down ~3 feet off the floor and found 2 next to each other leaking. I knocked the whole bottom row out and just plugged them all regardless. The installation was not wet, water leaked down the wall and under the bottom plate and didn't touch it. Regardless insulation is cheap so I just replaced it all in that area just in case. I installed new drywall, patched and painted it, and put the carpet back down. Annoying but an easy a very cheap repair and impossible to tell anything happened. Had I put installation against the wall I would have had a lot more work finding and repairing them. After that no more problems. Next time I would just hire a pro to come out and plug all my spots with tie rods before the walls are up to avoid any potential issues. Also check valves on all your floor drains in case those back up. Have your drain lines snaked and camera inspected. Install a drain pan on your water heater and humifier if you don't have a floor drain nearby the water will naturally flow to if there us a leak so it doesn't leak into your finished space. Upgrade your shut off valves to ball valves if you can and install frost free faucets for your hose bibs. Outside make sure your grading slopes away from the house and your downspouts are getting water away from the foundation.

As far as the floor went I did carpet in most of mine for comfort. I got the thickest anti microbial pad I could get (suggested for basements) directly over the concrete and it was very comfortable. I tiled a room too. There I painted on a rubberized coating to isolate the tile from any moment in the concrete and avoid cracking. If I had the ceiling height to lose a few inches I would have considered installing a snap together subfloor that had plastic channels on the bottom to allow water to flow to the floor drains in any got under it.

If I had a brand new home I would be a lot less concerned with water getting in through the walls as they use plastic tie rods now and are a lot better a water proofing. Same with the floors as there will be insulation under it. In that case I would still frame 1" off the wall and have someone come in and spray foam the walls right up into the rim joists. The reason I like spray foam over ridgid foam and tape is that the spray foam really gets into all the cracks and air seals the whole thing up. That keeps the bugs and critters out as well. A little more expensive but worth it in my opinion.

One area of my basement was also my woodshop. I left that area unfinished. I insulated and drywalled and painted the two walls separating it from the living space. Mostly to keep noise transmission down. The concrete walls I just painted, and I also sprayed the open joists/ceiling with white paint to lighten things up. I had a supply line for my forced air HVAC in there but no return that could suck up dust. That shop served me well until I had kids. At that point I couldn't work down there very often because of the noise. In the living area I finished I put insulation for sound proofing in the ceiling and drywalled the ceiling too. ( drop ceilings I'd have lost some height). That helped a lot but noise still traveled. If I could I would finish the work shop space too. There was a big temp difference between the finished/unfinished areas and noise control would have been better but still far for ideal. I eventually solved that issue by moving to a new home where I have a heated/cooled outbuilding that's soundproofed for my shop that I can work in at any time day or night without bothering anyone.

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jmiller320 t1_iybwd5e wrote

My basement walls are poured concrete and were wrapped with insulation with a vapor barrier. It came in a roll and was fastened to the wall with Ramset shot anchors. I used steel studs off set from the wall these were attached to the floor and ceiling joists. Only lost about eight inches in the room. Remember to level everything from the ceiling down as the floor might sloop.

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davidmoffitt t1_iybz4ag wrote

I’m in upstate NY, my answer was to use 2.5” metal studs held 1” off the wall (put the bottom channel on sill plate foam) and to apply 3” of closed cell spray foam. This ends up dimensionally the same as doing 2x4 framing (3.5 actual) directly against the wall but providers an air and moisture barrier, the foam stiffens the studs insanely well, has no organic materials to mold or rot from moisture gained by contact with concrete, and provides an EXCEPTIONALLY flat surface to drywall - which ok in a workshop isn’t as important ;)

Speaking of workshop stuff - I’d install some cross bracing (can just zip screw some ply or furring strips, notch for the rolled metal edge) where you intend to wall mount anything heavy like a metal pegboard full of tools - you can still drill through a metal stud and use toggles but I prefer pre-bracing.

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solsbarry t1_iycry0s wrote

Why are you finishing the walls for what will be a shop. Maybe you just want a project But I can't see why you wouldn't just leave it unfinished

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Ad-Nauseam91 OP t1_iyd3nnr wrote

The main reason so I have a good spot to hang things like cabinets, tools, etc. I want to avoid drilling into foundation often if I can.

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KeyStoneLighter t1_iyd8g0u wrote

I’m looking for the same answers but like in boise Idaho, any recommendations?

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PostingWithThis t1_iyfba49 wrote

I did this last year. I opted for pure EPS. It can be messy to work with but it is a great insulator and it breathes a little bit more than the others, which was a big plus for me. When you insulate on the inside of a concrete wall, it needs to be able to dry a little to the inside. I felt pure EPS was the best balance.

I’d say the rim joist boxes are really important and it sounds like these get overlooked often. Clean them out, seal all the edges and cracks, insulate them with EPS blocks, then seal around those too.

Also, just don’t get it too hot in there when it is cooler outside as this will cause condensation that doesn’t have a good path to drying.

edit: spray foam is terrible, wouldn’t touch it

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