Doorwall bay rotting against stamped concrete patio

[osprey41]

Hope some gurus can weigh in here.

I have a 6 year old house (pic attached) that's mostly brick, but is wood in a few areas like the doorwall bay (as shown). 4 years ago, had a stamped concrete patio installed right up to the bay. I believe a vapor barrier was put in place, but as you can imagine, the wood underneath the doorwall (both the trim directly underneath and supporting wood behind the trim) are now starting to rot. The patio covers up about 6" of the bay and is separated by (from what I can tell) only a fabric concrete expansion strip.


I've had several carpenters come out to quote on fixing it, but the estimates and fixes have varied from trying to take out the concrete steps and replacing wood with fake "PVC wood" to just chiseling out the rot, replacing the trim and flashing everything to prevent further water intrusion.
Any thoughts on the best path forward for repair? I may end up contracting out the work, but am not particularly savvy with regard to wood rot and making an appropriate fix. Perhaps it's something I can fix myself.


One other concern is that there is a small-ish air gap under the bay to gravel / earth / crushed concrete beneath - if I fixed the trim and prevented water intrusion from outside, will I still get burned by moisture under the bay? (The patio installed assured me no, but he was selling a patio).
Any thoughts are appreciated,


Steve

[pushkins]

Typically what should have happened is that the siding and trim were either removed or cut off above the proposed concrete line, then galvanized metal or rubber flashing added to the house, pour the concrete, stamp it etc... then and only then reinstall the trim and or siding allowing 1/2" between siding and concrete. this allows any moisture to harmlessly fall away and the galvanized flashing stops it getting back to the house wood.
What you have is the siding/trim sucking up any moisture it can get out of the concrete and a place for rain water to wick into.
Removing the trim/siding is problematic as it will leave a gap between concrete and house and replacing it with PVC trim/siding equally as problematic and still will allow moisture in (bigger problems down the track). You could add a small piece of drip edge to the wood, make sure you use a very good quality caulk, apply a bead on the wall and apply a bead on the concrete, position the drip edge/gal. 90 degree into the caulk and then screw the drip edge onto the siding. Once done add a bead of caulk across the entire top edge of the gal. strip.

[osprey41]

I'll definitely take a look at that suggestion. I know I need to replace the trim that's there and I can tell (from the poking at it I've done so far) that some of the wood behind the trim is rotted as well. My hope is to replace the trim and stop the water from getting at the wood - assuming most of the water is coming from above and against the patio and not from underneath (under the bay is crushed concrete, but not all the way up to the bay). I like the idea of the the drip edge caulked in. I can keep an eye on the water problem from the basement to see if the problem is resolved once any fix is made - the floor joists go all the way underneath the bay and there is a rim joist that looks like may have seen some water (but not rotted). Thank you for the reply.

[marijoy]

Wondering what happened

Osprey41, can you post what resolution you ended up finding? I recently had a patio installed and it is the same type (over a bay doorwall and closed in) as yours. I am very worried about future problems as it is a brand new house and we are not at all handy with this kind of stuff. Just wondering what you ended up doing and if anyone has any tips on preventing water intrusion with this type of patio set up. Thanks!

[osprey41]

I had a contractor come out and he pulled out the rotted board under the doorwall, added flashing, and put a piece of cedar in its place. Then caulked everything real tight to prevent any water from getting back behind the patio and rotting out the bottom of the bay. Only time will tell if the fix worked, but it certainly looks nice now. Hope that helps and good luck!

[marijoy]

Thank you for the fast response! Can you clarify - what is flashing? Also, did they have to tear out any of the concrete to replace the wood? If not, how did they get to the wood with the patio right there? Also, which board rotted? Finally, where did they caulk? On top of the vapor barrier or around the roof of the doorwall? Not sure if maybe we should try caulk for prevention. I am sorry for the millions of questions. I am really worried sick about this patio damaging our brand new house.

[pushkins]

It should be caulked (with an exterior grade silicone) at the joint between the concrete patio and the wall/siding.