Energy Audit Report - need advice

[loves2read]

Originally Posted by Katana49

Make sure you check with your HOA, as they may not allow turbines, ours doesn't. We can do solar powered fans that are less obtrusive.


As far as radiant barrier goes, there's 3 kinds, and only one of them is really worth the expense IMO. The first is what is being used on most houses built today, OSB radiant barrier. It's plywood with a layer of foil on one side. It's better than nothing at all, but it's the bare minimum as far as radiant barrier goes and it will not reduce attic temps as much as the next two choices do.


The second option is to have radiant barrier foil applied to the existing OSB (which may already have foil backing or not.) This RB foil is thicker and better than the backing on the OSB panels you see, and works a bit better, but is still a poor choice for controlling attic temps vs the next option.


The best option, is insulation board. This is a polyisocyanurate foam, with foil backing on one side. It has the greatest R value of anything you can attach to your roof, and it actually does make a dramatic difference in heat in the attic. R-max is one brand.


I've had all three kinds, and insulation board wins hands down. Ideally, it should be applied when the house is being built, but I've seen some companies retrofit it. Much better than the other options and it's a difference you can feel, attic temps can be 20-30 degrees cooler than the other options.

How is the insulation board applied in an attic with established roof sheathing and composition shingles?
Can you void your shingle warranty applying after the fact?

I think the HOA laws that went into effect about 4-5 yrs ago prohibits any HOA from having a rule that keeps homeowners from adding energy efficient features--like solar panels--even if they are visible from the street...
I would think turbines which promote ventilation in the attic could not be prohibited...

[Katana49]

Originally Posted by loves2read

How is the insulation board applied in an attic with established roof sheathing and composition shingles?
Can you void your shingle warranty applying after the fact?

I think the HOA laws that went into effect about 4-5 yrs ago prohibits any HOA from having a rule that keeps homeowners from adding energy efficient features--like solar panels--even if they are visible from the street...
I would think turbines which promote ventilation in the attic could not be prohibited...

These insulation panels are added to the underside of the roof, in the attic. My previous home, the nails from the shingles were enough to hold it to the plywood, it's about half an inch thick. If you were going to install it after the fact, using 1" or 3/4" nails would be sufficient to get hold it against the plywood but not go through to the shingles.

[loves2read]

Originally Posted by Katana49

These insulation panels are added to the underside of the roof, in the attic. My previous home, the nails from the shingles were enough to hold it to the plywood, it's about half an inch thick. If you were going to install it after the fact, using 1" or 3/4" nails would be sufficient to get hold it against the plywood but not go through to the shingles.

So how does that effect the shingles' warranty--retrofitted to hold heat close to the plywood shingles are nailed to???
I have heard that can affect the warrant

And is the FOIL part showing INSIDE the attic space or placed against the roof side?

[escanlan]

Originally Posted by loves2read

So how does that effect the shingles' warranty--retrofitted to hold heat close to the plywood shingles are nailed to??? I have heard that can affect the warrant


Many shingle manufacturers in the past have stipulated not to block free air flow on the underside of the decking to allow it to dry and reduce decking temperatures. That was in the past and when they started losing business from it they either reversed their decisions or became completely silent on the practice. If it is not specifically addressed in the shingle manufacturer's installation instructions, or other Tech Notes they provide, then the only way to know what their stand is with regards to the warranty question is actually contacting them with the question.


And is the FOIL part showing INSIDE the attic space or placed against the roof side?


The manufacturer of the specific product will dictate its installation requirements. One such product is the Johns Manville AP Foam Board Sheathing. You can read about its installation and many different requirements here Foam Board / Sheathing.

Answers and other in blue above.

[TheOverdog]

So how does that effect the shingles' warranty--retrofitted to hold heat close to the plywood shingles are nailed to???

It has no effect. There are tons of thin, valuted ceilings which have insulation up against plywood roof decking that has no real impact on shingle lifetimes. The best way to install foamboard decking is during the intial construction, as it goes underneath the plywood decking. Most re-shingle jobs don't rip off the plywood decking unless it is in terrible shape. The foil points upwards towards the sky. Most shingles in the southwest can sustain temps of 160F for 4-6 hours a day under normal use.

There are known issues with installing shingles in temps above 90F, but since roofers can't work at night, those are mostly ignored in TX in the summer.

[tcualum]

The paint is a scam. Have you looked at other options such as Solar Screens? We have them on the back side of our house which faces north. We didn't do the other 3 sides of our home since we have shade trees there. We also had them installed on our previous home. The amount they help your electric bill depends on how sunny the rooms are, which way your home is oriented and what thickness you choose. They have other benefits besides lowering your electric bill. The sun shining through the windows is less glaring and you have increased privacy. We used to have to close our blinds in the living room during the day because the sun coming through was so blinding and because we had no privacy. The neighbor behind us is at a higher elevation so his home literally looking into our home. Now they can't see in if the lights are off in the living room. I know that a lot of people don't like the look of them but we felt like the advantages outweighed the disadvantages.

[TeamLynn]

How long do you plan to be in the house?
How much electricity to you plan to save?....10% in the 3 hottest months....20%?
How much is your bill now.

Almost none of it probably makes economic sense unless you are in the house for a very very long time.

Maybe only the insulation makes sense if you are there for a while since it helps with both heating and cooling.
Do the vents when you get a new roof.
Seal the ductwork.

Spray on radiant barrier is probably what they want to do and probably doesn't help you at all but maybe makes you feel good. Now this does help a LOT if you are building a new house.

The house has no soffit vents now? If that is the case, then the house and style of the roof might work for ridge vents. You get that when you reroof. Maybe you get that free when you replace the roof if your insurance company is paying?