Expert: Bruce E. Johnson - 1/12/2009

Question
Hi, I own a 1945 brick Tudor home in Washington state. The basement recently flooded and I peeled off some old paneling and it revealed a black paper covered "backer board" between the brick facade and the interior studs. That backer board has crumbled in some places. My question:Is the backer board used in that era water resistant? Should it be replaced?

Answer
Hi Patrick, I'm not sure what that material is, possibly denny board.  Denny board was made of fibers and impregnated with some sort of tar.  If that's the case it was kind of water resistant way back when.  The problem with flooding is that with the water comes bacteria and other stuff from septic tanks etc.  Killing all that potential mold producing material is just as important as drying it out.  I recommend removing all wall coverings in the flooded areas that got wet.  Allowing the internal studs or furring to dry and then after a good bleaching and cleaning, replace the wall coverings.  I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com