House construction

[Jerrymac]

Looking for answer to a question about attic ventilation. If you have seen my pictures under the topic "after the Storm" you know I am in the process of doing a lot of repairs. And I am attempting to improve things about this house. One of the problems (I thought) was water (or snow) coming in the top of the windows when it would rain. (The snow a problem after it started melting.)

Have you ever experienced horizontal rain (or snow)? You know it is pouring down rain and the wind is whipping along faster than most people drive. This mostly happens around here with a wind from the north. Wind blowing, raining, and in a bit water would be dripping down inside all the north windows of the house. Keep that in mind.... ALL OF THEM.

So after the storm we pulled all the damaged siding off the house and removed the windows. I noticed they were well caulked (All of them were). I didn't see any way for water to get around them. We are talking a lot of water when it rains or when the snow melts.

Here is my other conclusion. The soffits on the house has more holes in it than this picture I found...



And I am wondering about the possibility of the wind creating a vacuum on the south side of the house and sucking in the horizontal rain/snow through the holes on the north side. It then deposits the water behind that first board where it then goes down into the wall and drips in the windows. These are not my house just some pictures I found to illustrate.



I know I know. If I am correct that means this also has been happening inside the wall where there are no windows. 

So I am wondering, down here in the south where it doesn't get all that cold and is dry most of the time, I could go with less ventilation and rig it so the horizontal rains can't get in..... right? 

[buzzbee]

Would spouting on the house divert enough of the water from the roof runoff to help with this? My home has a 1 foot overhang and a gutter system to direct the water to downspouts. It would have top help make kless water to blow against the house.

[Jerrymac]

That might help a bit but there is still the horizontal rain

[hardwood]

For over thirty years I've been building homes on the beach here in central Fl and we have the same problem. Strong winds creat a negative pressure on the lee side of the house and a positive pressure on the windward side. At times it's strong enough to suck the water right past the seals of the windows and doors (especially sliders) and can certainly suck water up through the passive roof venting. I don't know what your insurance will cover but I've found that using iconene foam or one of the new soy based foam insulation systems stop the problems.

What happens in these systems closes all of the roof venting and makes the attic a "semi conditioned" area and dramatically reduces the pressure differences. It's not cheap, but can save you tons in the long run in heat gain/loss. Check into it.

Scott

[Jerrymac]

This is that stuff that sprays in wet, swells up, and then dries rather hard? Does this also eliminate the moisture problem the ventilation is suppose to take care of?

Keep in mind I only have about six inches or so of space between the ceiling and the roof. Just fill it full of this stuff?

[hardwood]

Yes and yes.

Scott

[Jerrymac]

I was looking at a video of that being sprayed on. Is there just the one way to apply the stuff? Would I have to rip out the whole ceiling to spray it up in there or can it be piped in with a long nozzle? It is about 14 feet to the center of the roof from front and back. If they were going to go in from the side.

[hardwood]

I'm not sure of what all means they have for application. The only retrofit I've done with the foam had a large enough attic to stand up in. They first have to remove any existing insulation and then block the passive venting with a screen-like material that the foam sticks to.

Find a local applicator and ask for a quote.

Scott

[Jerrymac]

OK thanks