I recently had a concrete drive poured and it was poured up against the wood siding. Should this be caulked where the wood meets the concrete? If so what type of caulk should be used and should I caulk before or after I paint? Below is the photo.

Photo of siding and drive

1 Answer 1


Wood meeting concrete in a damp area is never a good recipe. As porous as concrete is, its not even ideal that treated wood meets concrete. this is mostly because of the chance for standing water or leeching.

My recommendation in this scenario would be to trim the wood siding ~1/4 inch minimally, or better yet 6" to 8" above the concrete area. If you go inches, (which you should) install aluminum flashing (for example).

After doing the trimming, you should use flashing or caulk as you suggested to not so much as seal it off, but while sealing it off, make a curved bead that directs water away from the wood.

I would have thought ideally the contractor would have put expansion strips here right along the side, and ideally should have discussed with you the height of the concrete once cured and what the plans were for water control and keeping it off of the structure.

What you have there now is going to rot, caulking it would slow it down from the outside, but underneath it would probably accelerate it since the moisture will wick up behind the caulk and up the siding.

Here is a quick google search of water wicking up wood: http://www.cwfbuilders.com/images/Water_damage_at_walls_from_patio.JPG

Here is just one of many views yours could look like with flashing. Just picture it is a slab instead of a deck, Also, consider direction of travel for water. In this photo while it gives you and idea, the trim strip is not something you'd install on top, this is just a pictoral reference form anotehr quick google: http://decks.blob.core.windows.net/img/articles/large/16011219304064.jpg

  • Here's an added link I found while trying for some more photos... this may be of some use since it actually kind of talks to all of this: doityourself.com/forum/exterior-paneling-all-exterior-sidings/…
    – noybman
    Sep 21, 2017 at 3:49
  • The concrete as poured seems to create a covered soil-wood connection. In some areas this is an invitation to termites.
    – DJohnM
    Sep 21, 2017 at 5:10
  • Between the trees, the roof overhang and pitch it only gets wet if my wife hoses off the driveway. We had to pitch away from the house, the garage and the neighbor and it was pitched correctly but this needed to be the highest point. He did trim the siding before it was poured and I would guess there's no more than 1/2" of siding below the top of the concrete. I'll trim the siding and flash it, this and the other side is only about 6' total. Sep 21, 2017 at 19:17
  • The part you have pictured is 15" easy, it looks like it bends further and runs more. If you are saying you will only trim the edges you believe will get wet, I strongly advise against that. None of the siding should touch the concrete ANYWHERE in any area or environment.Think of the slab of concrete as a giant sponge with corrosive chemicals in it. As water exists UNDER the sponge, the sponge will suck it up and so would wood sitting on top of a sponge. It is not just moisture from above that you have to be aware of.
    – noybman
    Sep 22, 2017 at 3:57
  • I probably didn't word that well, for appearance sake I plan to flash all the siding where there's concrete whether it touches the concrete or not. It's three small areas, what's pictured, two feet around the corner and about two feet on the other side of the garage. Those are the only parts of the garage where there's concrete. The rest of the garage siding is a few inches away from the ground. Sep 22, 2017 at 14:52

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