Sorry for the delay, been extremely busy lately.

It is not likely the foam will remain wet, the whole idea behind using spray foam is that it prevents moisture from going through your wall – the foam – hence why you see drywall contractors putting drywall directly over sprayed walls without a vapour barrier on shows like Holmes on Homes. What can happen is that the spray foam may separate from structural lumber and plywood etc and water and moisture could remain in these spaces eventually causing rot and mold – having the house dried professionally can prevent this but you will need a professional with high tech equipment to test afterwards for any moisture that may remain in the home. In all cases, nothing should be covered up until completely dry!

Any contractor telling you the insulating foam will remain wet must be using an alternate product. Ask what kind of product they are using???

Regular insulation, once wet needs to be replaced (rock wool is an exception and can sometimes be dried depending on the severity of the flood damage). No matter what type you use it is a must to get a professional in to dry the basement out properly with the right equipment – don’t be surprised if they recommend removal of flooring, drywall and insulation on the bottom half of any walls that get wet (or the whole wall if the water damage reached the ceiling). If you don’t do this, expect serious rot and mold issues in the future.

Thanks for the questions, good ones too!

Firstly, in regards to your attic… Any roofer that tells you moisture will collect on the sheathing is not experienced in proper ventilation of attic space (the only way this happens is if you are missing a vapour barrier on your ceilings). The actual vapour barrier between an attic space and your living space is on the ceiling joists behind the drywall (or other finish). The moisture builds on the attic side of this vapour barrier. This moisture in turn is dried out with proper ventilation in the attic space which should be sized to the cubic footage of the attic and climate of the area you live. In addition, proper insulation prevents the cold air from contacting the warm surface of your ceilings and thus reduces the amount of moisture that will accumulate on the vapour barrier. This is why it is so important to have a very well sealed vapour barrier and insulated attic- any exposed area will cause moisture damage over time.

As far as where to spray foam in the attic, contact a pro with excellent references. My experience would lean toward spraying between the ceiling joists and not the rafters but your locations, roof design etc all need to be taken into consideration – call a pro in your area to finalize your decision.

The basement is an easy answer – NO! Pay the money and do it right – stop the water from the outside first (even if this means waiting a while if you don’t have the funds). Once dry, go ahead with the inside work. Painting is not likely to be a good idea as the foam would then adhere to the paint and not the blocks and I think the seal and adhesion of the foam directly to brick would be better – again, contact a professional spray foam contractor for the final word – they may recommend a coating, but I think more than likely, they will spray directly on the brick.

Remember, the cost of water damage can get out of hand very easy, do it right and fix it before spending money inside your home.

Hope this helps

Some contractors will spray between the Rafters, right on back of the decking, but others observe that the roof sheathing will tend to rot, due to not having anywhere for the moisture that finds its way towards the attic from shingles. Water vapour doesn’t sleep i hear :^) .

Should the floor of an atiic be sptrayed or should be go for a hybrid sheeting over the rafters to duct air between the soffits and a ridge vent, and try to at least keep some mid temp air in the attic?

There IS A HUGE oppty for a roofing solution. What do you all think about that?

Also, for basement, I have cinderblock walled basement that seems a little porous… it seems to be more than condensation. Can I paint over the block and then spray over that, once the water seepage is controlled better?

Digging out the foundation and putting in the vapour barrier on outside is about $100 a linear foot. Ouch!

THanks!!

John Westerdale

If this (total flooding) happens again, and this foam is on the walls and the ceiling of our basement, will the foam become saturated with the water and stay saturated with the water even after it recedes? I was told that once wet, this remains wet…

Please let me know. Thanks in advance.

Clarke