rotten subfloor under load bering wall


Old 07-27-07, 05:00 PM
Thread Starter
Join Date: Jul 2007
Posts: 4
rotten subfloor under load bering wall

I had a sunroom that leaked. To fix this problem I had the room taken down and conventional framing put in its place. The room sits above my garage. The sub floor is rotten in a few places. I was simply going to replace the rotten places when I realized that the subfloor is rotten unter the wall. How do I replace the subfloor under a wall? My concern is that over time the new room will drop 3/4 inches, the thickness of the subfloor. The subfloor is not wet anymore but is soft most of the length of one wall and in the outside corner. I was told that I could use a cement type product and cram it between the floor joists the bottom of the wall. I have had no luck finding a product for this application. Is this possible? What are my other options?

Your help is greatly appreciated
Sponsored Links
Old 07-27-07, 05:20 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,968
Welcome to the forums! is the room completed, including the roof? It would have been easier to replace the subflooring prior to building the room, but, now you have a challenge. How much of the subflooring is damaged under the wall? Injecting things won't help with the compaction that will take place eventually. If the area is relatively small, you can take out the offending subflooring, cutting the nails as you go, and install a piece that will span at least 3 floor joists and slide it under the opening you created under the bottom plate. You may have to use a couple of shims on either side to "lift" the wall slightly to get in the new subflooring, but it is doable.
Old 07-29-07, 12:36 PM
Thread Starter
Join Date: Jul 2007
Posts: 4
The exterior of the room is finished, including roofing. I had this done and was going to do the inerior work myself. When I was ripping out tile flooring I noticed the rotten sub floor. The wall is about 14 feet long. The rot runs the majority of the length of the wall. There seems to be about 3 feet that is solid. There is a garage under this room so I can acess the floor from underneath.

Alternately could I remove the rotten sub floor underneath the bottom plate. Then use 2X10s, or other dimension, cut to fit between the joists and anchor them to the floor joists. The bottom plate would rest on these 2X10s instead of the sub floor. I was also thinking of using a couple of 2x4s nailed together then getting a heavy duty angle iron to support the 2X4s. The angle Iron would be bolted through the floor joist. Are these options feasable?

I have also seem "EZshims" online. They claim to support 8000lbs. Could these be used between the floor joists and the bottom plate? would this prevent compaction?
Old 08-07-07, 03:00 PM
Thread Starter
Join Date: Jul 2007
Posts: 4
Ok I broke down and did it chandler's way. I was pleasently surprised that it was easier than I dreded. I was able to get the new subfloor about 2 inches under the bottom plate. And I replaced all but about 2 feet of the 14 feet wall length. My next step is to put 2X10s to help support the new subfloor and the wall in between the floor joists and under the bottom plate and top plate of the garage. Some of the 2X10 that the floor joists are attached too is a little soft, don't know the term for this. I will also sister some of the floor joists. Some have told me this is overkill but I tend to be conservative.

Thanks for the advice and help.

Thread Tools
Search this Thread
Display Modes
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -7. The time now is 01:34 AM.