Expert: Bruce E. Johnson - 7/24/2009

Question
I had some bad siding, and after removing it, I noticed the wall behind was kind of rotted at the bottom where it meets the porch. It also looks like the felt is torn so I'm not sure if it was left this way or rotted. Should I just take some felt and nail a piece on that extends further. I'm not sure what kind of board that is behind the felt.

Here are two pictures(clicking on the pics should enlarge them even further). http://tinypic.com/a/xzb4/4

Thanks

Answer
Hi KC, It looks like particle board or denny board behind the felt but I can't say for sure.  I would definitely cut the felt back and see if the wood or whatever your subsheathing is made of needs to be replaced.  It is showing signs of rot and while you have the wall opened up now it the time to fix it.  You can just cut out the bad stuff and replace.  The rotted material may only be 6-8" high, snap a line or level a line across and cut it out.  Once you have the rotten wood replaced slip your new felt paper up underneath the existing felt paper before siding.  This allows any water that gets behind the siding to shed down and seep out instead of getting trapped behind the felt and causing further damage.  I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com