The Dumb Things DIYers Do...

[dmccarty]

About Attic Ventilation : ENERGY STAR

I would use a better reference. Here is one:
BSD-135: Ice Dams — Building Science Information

Lsiturek is a Phd and PE and studies, researches and writes about Building Science with a company called Building Science. I used his design details from one of his books that matches the climate in my area to build my house. He got me thinking about using a sealed attic which is a wacky idea. Until you start reading the research.

If your ceiling is hot in the summer then you are using power to to cool down your house. In the winter you will have to spend more money to heat up the house. I would think more insulation would save money winter and summer. In my area I am supposed to have around R35-45 in the attic. Can't remember which since the guidelines seem to change. But we have the recommended amount and I do not feel a temperature difference on the ceiling. I did feel a difference in our old city house which did NOT have enough insulation. The house we build is twice the square footage as the city house but over 60% more in volume. But our energy costs are about 30% LESS. And the reason is better insulation. The new house would be much more energy efficient but we wanted WINDOWS. The city house had four windows and one sliding glass door. The new house has more window square foot in the living room than in the entire old house. Good for viewing. Not so much for being energy efficient.

Concern about the heat on the shingles is good. But the real issue is money. Which is going to cost/save more money? A sealed attic which should save energy costs? Or the possible reduced lifetime because of the extra heat on the roof deck. The link I posted about mentions energy savings. I know in another Lstiburek study the extra heat on the shingles was not very much, like in the posted link, and that the reduced shingle lifetime would be minimal if any.

I have no idea if one should seal an existing attic. I just read up on them when I was designing our house. Again I did not do this on our house because it was going to be a battle with the county. This sort of stuff is always a balancing act so in the end the scales were tipped in favor of having a vented attic. But I do think it costs me money in the summer due to increased AC costs. However we only use the HVAC during the summer so the overall cost for us is minimal.

A great resource on building issues is:
Building Science Consulting

Later,
Dan

 

[Dadsgreenpsd]

I do home inspections, and am an electrician, and find quite a few do-it-yourself fixes. I post some of the better pictures on my web page. I especially like it when they purchase extension cords to wire new outlets.... That wire is so cheap, you know... Masonry chimneys built on wooden shelves, plumbing vented into the attic, bathroom fans vented into the attic. Duct tape, masking tape, and electrical tape, none of which are used correctly. And how hard is it to use a romex connector???

 

[Travelover]

...........I have no idea if one should seal an existing attic. I just read up on them when I was designing our house. ..........Later, Dan

OK, if you want to seal up your attic, go for it.

 

[wykubotaguy]

And how hard is it to use a romex connector???

Really hard or so I have seen. 4/0 urd run through a 2" ko with no connector, outdoors and 4' down the wall w/o pipe into the ground!:thumbdown:
Bird, on the knob and tube. I guy i work with was in Sheridan, Wy and had a service call with a journeyman where the customer was complaing about power issues in a room. They looked in the attice and didn't need a flashlight!!!!!!!!! The insulation had fallen off because the wire was bright red like toaster filaments! It had burnt trails through the blown in insulation. Needless to say they told the homeowner to turn off all the power and get a complete rewire.:thumbsup: