Garage wall rot

[G-ZUS]

I have a detached garage that is sitting on top of poured concrete. Right on top of concrete there are horizontal 2x4s. There is no concrete lip around the edge of the pad.

The bottom few inches of the plywood are rotting, similar to what is seen in the attached pic. What can be done to fix this?

[KPHMPH]

You need to replace it all and put a plastic barrier between the concrete and wood.

[AndyL]

I believe they prefer that breathable foam stuff to the pure plastic these days. Still a barrier but allows airflow.

What's the grading like outside? That moisture has gotten a ways up for wicking from concrete...

[s_havinga]

Are you shoveling snow up against the outside of the wall? Or is the grass higher then the pad? No different than a house you need to make sure the grade of your lot is away from the garage. Building a garage right on the slab is very common, this issue seems to be that you must have a lot of water pooling on the other side.

[sexualbanana]

+1

I'm anticipating the same problem in my parents' garage. Interior water (dripping off cars and whatnot) seems to pool up in a couple corners with no drainage. Any insight on what to do and what to watch out for would be helpful.

[G-ZUS]

I recently bought the house. On one side, the garage is about 6 inches below grade and there is a concrete walkway. On the other wall, the wall is about a foot or so below grade and there is a wooden greenhouse built against this wall and a wooden riser.

[ExtraSlow]

I'm following this thread as my garage has water inside that pools in a corner and causes similar issues.

[firebane]

Ugh dealing with this same crap in my garage. W, N, and E side the ground is all level with the top of the pad so last winter the snow melted and flooded my garage. South side was fine as it was lower than the rest.

[G-ZUS]

I had one guy come out and look at it, he said we can cut pieces of pressure treated wood to size and glue them on then fill the cracks with expanding foam for a temporary-ish fix?

Permanent fix would be to jack up the garage and build a footer, which would be $$$. then taking off the siding and changing out the plywood to pressure treated and re-applying the siding.


Any other (cheaper) options here? Would lowering the ground around the garage and sloping it away work?

[s_havinga]

Assuming that the water is coming in from the outside (which I expect) and not pooling from the inside as other have suggested (which is also totally possible, it just seems like a ton of water for that scenario) I would say lowering ground an sloping away would be the proper solution. If the wall stays dry after that, there is no reason for PT plywood. You could also probably dig a ditch and install some weeping tile and gravel to allow proper drainage but If lowering the grade is an option, I would go with that one.

[Kloubek]

Grading it away from the garage is best, for sure. But instead (or in addition to) you might want to put that plastic dimpled wrap on the outside where it is going to be below grade. That will keep the water from coming in.

Then as far as this rot is concerned, you need to take it out and replace. If you take care of the water problem, it doesn't need to be pressure treated. I would imagine the plywood might require replacing as well. And when replacing, put plastic under it as there should have been in the first place because concrete wicks moisture so even if you fix it, the concrete will likely produce some level of moisture anyway.

[sexualbanana]

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Permanent fix would be to jack up the garage and build a footer, which would be $$$. then taking off the siding and changing out the plywood to pressure treated and re-applying the siding.

Would it be cheaper to just tear down the garage and re-build? Honest question. I have no idea.

[G-ZUS]

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Would it be cheaper to just tear down the garage and re-build? Honest question. I have no idea.

~5K to fix it VS. ~18k for a new garage

[roopi]

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~5K to fix it VS. ~18k for a new garage

5k is to jack it up and build footer?

Personally I would fix the grade as suggested and add drainage. Once you no longer have water coming in then I would look at repairing the rotting wood. No point in fixing any of the wood until the water issue is fixed. If the water keeps draining towards the garage it doesn't matter about the pressure treated wood/plastic/etc it will eventually cause damage.

[AndyL]

Depends if you're DIY ing or paying someone...

You can jack a wall at a time replace the lumber - sheeting - you're kinda screwed on, means taking a few courses at least. (Remember its usually installed bottom up so depending on kind - could be possible/impossible/other) but some have just pl'd the new lumber to old sheeting and cut away screws or nails that interfere.

Kinda depends on the shape, one could knock it down and rebuild at near the same cost - especially when you consider the kit would come with new roof and siding.