Used mastic to repair holes in front steps, eternally sticky and causing a mess now

Submitted by RoarBacon t3_z810bs in DIY

Hi,

I've used a 'quick drying' mastic to fill holes in the steps that lead up to my front door as there was a leak underneath, the leak has stopped, but the floor is really tacky, and in the rain black liquid is pooling, and i've clearly used the wrong thing. Will it ever dry? Do I need to seal/treat the top with something else, or is it in scrape-out and try again territory. Any help would be MASSIVE.

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Comments

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housebird350 t1_iy9cna0 wrote

I would scrape it out and use mortar, not mastic. You can also use "patchcrete" its already mixed and comes in smaller tubs if the repair is fairly small, it will keep you from having to buy a 60lb bag.

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SpaceGoonie t1_iya9beu wrote

Also, make sure it's freeze thaw stable. Many are for indoor use only.

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SatanLifeProTips t1_iy9zvgt wrote

If it’s the gap between concrete stairs and a home you NEVER use mortar. The home and stairs have different thermal expansion characteristics. You need a sealant that remains soft and pliable.

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housebird350 t1_iya07lj wrote

Thats not what OP said though, he said holes IN THE STEPS, not the joint between the steps and the house.

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SatanLifeProTips t1_iya0emc wrote

Did you read what I said before you downvoted me?

I read what the OP posted and felt it was important to add a disclaimer for the house to steps connection.

Edit: we are also both assuming concrete steps. But the OP doesn’t even say what kind of steps they are.

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MyNameIsRay t1_iy9b4bk wrote

Did you ensure the areas you were filling were cleaned and dried before adding the mastic? If not, all that moisture that's now trapped inside will prevent curing.

This is probably a scrape out/re-do scenario, but even that won't work if the issue is the ambient moisture levels or quick exposure to water (like rain after you apply, sprinklers, morning dew, etc)

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RoarBacon OP t1_iya2qid wrote

Thank you this is really helpful, fundamentally it will get rained on so might need a different solution.

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xo-laur t1_iyagota wrote

Could be wrong, but pretty sure the person above means that the problem is rain/moisture too soon after it is applied. Not rain/moisture in general. The product needs to remain dry until it’s fully cured, otherwise the excess moisture will cause it to stay malleable/messy.

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l397flake t1_iyaouq0 wrote

What are the steps made of?

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Stockmom42 t1_iyabn5o wrote

Mastic is garbage!!!!

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Petd80 t1_iya9idy wrote

Fast and dirty, meaning that I wouldn’t do it for a client or try to get paid for it - get a sheet of 3/4 cdx - cut out pieces that match the stairs - screw it together and drop it on top. Secure w expansion bolts. It’ll last a couple of years. Wouldn't try with more than 3 steps.

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sleaklight t1_iybf5zn wrote

What kind of mastic did you use? There's a type that never ever dries and that seems to be one you have used. We call it wet patch.

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jawshoeaw t1_iybvl67 wrote

I hate mastic so much. It loves water ! Scrape it out and use concrete or bondo

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