# Waterproofing slab porch that covers foundation



## nearlycivil (Mar 29, 2014)

Hi All,

I have 1951 Cape Code with a cement slab porch that rests on a cinder block foundation (i.e., the basement extends under the porch). An outer corner of the porch slab, next to the downspout, is cracked and allowing water into the foundation. The seam where the slab meets the house will allow water into the basement in a driving rain. House is in southern Michigan. 

I would like to waterproof these areas ASAP. Any recommendations on how to proceed? Here's what I got:

1) Remove planks from wooden porch for access. Keep the frame of the porch intact. See image porch_overview.jpg.

2) Build out wet corner (see image porch_leaking_corner.jpg). What cement product should I use? 

3) Seal slab seam that adjoins house. If the pitch of the slab is wrong, how to correct? What product should I use to seal this seam?

4) Is there additional water proofing I should do to the slab while I have access? I plan to paint the porch, foundation and to powerwash the house once I've got the water issue taken care of.

Thanks!


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## nearlycivil (Mar 29, 2014)

Here's a pic from inside the basement looking at the wet corner. Note discoloration. No need to repair the foundation, right? Please say yes.


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## Canarywood1 (May 5, 2012)

You can also use epoxy to fix the leak, watch the video in the link.


http://www.mudsupply.com/Simpson-St...n-p/3719.htm?gclid=CN7jjMm7uL0CFU4R7AoddTQASA


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## nearlycivil (Mar 29, 2014)

Progress report and request for feedback. Plan is to remove the decking and use Black Jack asphalt roof cement with mesh tape to seal the areas along the outer edge of the porch where previously applied cement fixes are cracking. This might screw up water drainage. 









Where the slab meets the house I've got masonry silicone and will lay a bead (thick as possible) along the length. Of course, the siding is in the way. How would you deal with this part?


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## stadry (Jun 20, 2009)

not so fast,,, nothing you can apply to the inside will stop water from penetrating your home's very fine basement wall :no: it will PROBABLY hide it from interior view & from reappearing at the same location but ( trust me on this ) you will continue to see the problem :yes:

no matter who's product you put there, water will still run downhill :thumbsup:


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## stadry (Jun 20, 2009)

sorry to be late to the dance,,, very busy w/work ( conc repairs & bsmt wtrproofing stuff )

UNLESS you can guarantee yourself there will NEVER be any movement where you put the black ****, don't use it - its not flexible & will eventually crack so you'll be back where you started,,, we use either hlm500 or hydralastic - either is a great product - as permanent as you can buy, bridges cracks, has great adhesion to a properly prepp'd surface, & is elastomeric,,, for what it does, either product's very cheap.

you could also use ' herculiner ' truck bedliner - those guys are in chicago - find 'em on ebay [ no $ interest in either product ]

your choice to redirect any water ( drainage ),,, just remember it runs downhill, seeks its own level, & takes the path of least resistance :thumbsup:

1 last thing - stay OUT of apron/vest stores,,, IF you want pro results, go to where pro's buy :thumbup:


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## nearlycivil (Mar 29, 2014)

itsreallyconc said:


> use either hlm500 or hydralastic - either is a great product - as permanent as you can buy, bridges cracks, has great adhesion to a properly prepp'd surface, & is elastomeric


The hyrdralastic looks like a good tip. If I went that route could I leave the sleeper boards down and seal around them? In that case, a driving rain might leave puddles but that only happens a few times a year. I'm looking for a 5-10 year solution.


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## stadry (Jun 20, 2009)

not knowing your location, i have no idea - that's why you were asked to incl it

i don't like it when anything under OUR roof gets wet even it if only happens a few times a year :furious: maybe that's just me, tho,,, there is no 5 - 10yr solution,,, 1 either repairs it correctly OR keeps dicking around w/it when failure occurs


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## nearlycivil (Mar 29, 2014)

House is in Southern Michigan. I did include it in the OP (even read the instructions before posting here ).


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## stadry (Jun 20, 2009)

miss'd it - look'd @ your logon only,,, apologies !


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## nearlycivil (Mar 29, 2014)

itsreallyconc said:


> miss'd it - look'd @ your logon only,,, apologies !


I've also updated my profile. Didn't realize that's where folks looked.


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