Attic Venting and Roofing Questions

[pb4uski]

I recently purchased a home in coastal South Carolina and we have little need for ice dam protection. The previous owner had the attic foam insulated...spray foam on the "ceiling" of the attic and all fiberglass insulation removed between the attic and the house. This makes the attic part of the house interior. Also, all attic venting was removed/sealed. They stored art work in the attic because the area was dry and comfortable even during the hot summers. That is a common energy reduction solution in this part of the country, and our energy bills are less than $130/month for a 3000 sq ft home. This would be a significant change to your current arrangement, but might be something to look into.

That is similar to what we have. I've heard it referred to as a "hot" roof. We had spray foam insulation sprayed to the underside of the roof deck between the roof joists, as well as all the exterior wall cavities. We had to have an air exchange system installed because the house is so tight. As a result we don't have any venting on the eaves.

And it is very energy efficient.

 

[lakehawk]

Mold in attic

This is an excellent show which may fix your problem.

 

[MC Rider]

Nice.

 

[68bucks]

I looked at your eyebrow vents and that looks like the cats ass for your problem. Easy enough to do any roofer should be able to figure that out. Ridge vent and your done. I'd avoid a powered fan. If your ceiling isn't sealed well you may well be sucking air from the house that you paid to heat or cool. Gable vents sort of cross flow air and you really want botton to top. Don't know if it was mentioned but make sure you bathroom vents and such are vented through the roof not into the attic. I had that problem. If the deck is solid a mild bleach solution will kill and remove mold. If it stays dry it won't grow back. Lots of YouTube videos on that. I mean if you're in Arizona or Alaska there maybe some special things to consider, heat, heavy snow, extended extreme cold, but generally it's not that complicated. Just my 2 cents.

 

[chas 615]

roof ventilation

I

It is coming time to have my roof redone. I have several issues that I would like to try to address if possible.

The design of my attic is not right. There are not soffits and consequently no soffit vents. Before the last roofing in 1989, there was only a 2.5 x 2.5 square with an attic fan on one gable and a smaller opening on the other gable. The attic had gotten very hot and a lot of the decking had delaminated.

The roofers in 1989 put a ridge vent on the top. I realize that this is not right since the gable fan will draw air in from the ridge vent instead of letting hot air rise out.

My house is made up of the original part, plus and addition bedroom over den part.

Since it seemed to not have enough intake area, I thought it would be a good idea to pull down the attic stairs to allow air to flow up to the attic through the stair opening.

I went up there today to check for leaks and saw that the decking on the north side of the roof is black, probably mold. I don't think it is from any leaking. However, the lower four or six feet of the plywood is ok. That is covered by ice and water shield under the shingles.

I think that what has happened is that by opening the stairs, in the middle of the attic (on the original side) I created an air flow that blocked off any air that would come in from the small gable vent on the addition side. Maybe some moisture condensed on the colder north side and made the mold.

I only open the stairs in the summer when it is really hot.

I have two layers of pink insulation properly installed on the floor of the attic. That is moisture barrier down on the bottom layer and no moisture barrier on the top layer.

So, that is the current situation. Any thoughts?

If you have no overhangs there are currently products on the market to add intake ventilation on the roof. Either Smart vent or a Certainteed product edge vent will work. The roofer will cut an opening into the roof near the eve edge. the vent mounts on top of this opening. shingles are applied over top. It works in conjunction with the ridge vent.

 

[joesxm3]

Thanks for the idea, but I worry that cutting holes low on the roof will make problems with ice dams and winter water build up. Great for warmer areas though.

 

[chas 615]

Thanks for the idea, but I worry that cutting holes low on the roof will make problems with ice dams and winter water build up. Great for warmer areas though.

I live in mid Michigan Detroit area. Roofing companies here have been installing both products for over ten years with no issues if done to products specifications, Good Luck

 

[joesxm3]

I will take a look. Probably will not do roof until next year. So have some time.

 

[OldShooter]

... I sort of know the town guy who does the building permits. I think I should ask him if he has any suggestions.

This. SGOTI, without a physical inspection or (at least) pictures, is not a source I would trust. If you can wheedle a few names from the inspections department that would be best. Ideally, general contractors but insulation specialist companies might have some expertise too. Another option might be experienced house inspectors. I would not expect roofers to know much beyond folklore and oral tradition.