House built in 2001, 1 story, single pane windows.

Just trying to see what I can do to help cool the house better or help the AC not have to run all the time.

Windows are on the to do list but not in the budget right now.

How much insulation should I have? It's blown in, and currently I believe it's 14" but I'll have to double check.

Just curious if it would help if I added more insulation? If I remember correctly it's quite easy to rent the machine and from Home Depot and do it yourself.

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How much insulation should I have?

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As much as you can afford up to about R40 in my opinion. Somewhere in there the cost benefit falls apart, but up to there, it's good.

How many west facing windows ?

17 year old HVAC system ?

Sq ft of house and what ton system ?

It may not apply to your situation but one thing I am looking at is an attic tent for my attic access point.

My thermostat AND return air vent is located in the hallway, and the attic access is directly above. It's not a tight seal (house built in 1978) and I believe the return air is constantly sucking warm air from the attic.

One of these days I'm going to buy it off amazon and install it.

R38 is kind of the standar now (per payless insulation). I suggest not going fiberglass as it settles and you lose R over time.

You can save some money doing yourself, in my low pitch roof situation, I wanted no part of DIY

JP76 said:

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How many west facing windows ?
Not a ton, just a handful, as we essentially sit north to south, as far front to back of the house
17 year old HVAC system ?

Sorry forgot to include that, 3.5yr old 5 ton, 13 seer condenser. Coil replaced about 3 weeks ago.

Sq ft of house and what ton system ?

2500sqft, 5 ton.

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NCNJ1217 said:

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It may not apply to your situation but one thing I am looking at is an attic tent for my attic access point.

My thermostat AND return air vent is located in the hallway, and the attic access is directly above. It's not a tight seal (house built in 1978) and I believe the return air is constantly sucking warm air from the attic.

One of these days I'm going to buy it off amazon and install it.

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Ours is in a separate hallway from the attic stairs but I've been considering one of these as well.

sawemoffshort07 said:

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R38 is kind of the standar now (per payless insulation). I suggest not going fiberglass as it settles and you lose R over time.

You can save some money doing yourself, in my low pitch roof situation, I wanted no part of DIY

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Our attic is pretty accessible. That said, I'd have to price it to see if it's worth my time or not, no idea on the difference.

fire09 said:

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Radiant barriers were probably the biggest improvement I made to my 2004 build. That said, I already had double pane windows and a well insulated attic.

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I figured insulation was the easier first step and more cost friendly but definitely not opposed to radiant.

I just DIY'd blown-in cellulose and it wasn't terrible. I spent about $270 on my roughly 2,000 sq ft attic to add an extra R25 (8"). Took about 1.5-2 hours.

Blown in insulation is ~3.7 r value per inch so if you have 14 inches that should be okay. I like to see at least 11 inches if in an area where summers hit 95+ degrees.

How hot is it In your attic when it is 95-100 outside?
What type of ventilation does it have?

I've had good success dropping attic temps 15-20 degrees in my customers homes by improving attic ventilation. Did one last week where the builder had installed ridge vents over felt and never cut the decking back properly. At 95 degrees outside attic temp dropped from 138 to 118 after opening it up.



Do you have soffit vents in the eaves?

mneisch said:

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I just DIY'd blown-in cellulose and it wasn't terrible. I spent about $270 on my roughly 2,000 sq ft attic to add an extra R25 (8"). Took about 1.5-2 hours.

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That's nothing $ wise

JP76 said:

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Blown in insulation is ~3.7 r value per inch so if you have 14 inches that should be okay. I like to see at least 11 inches if in an area where summers hit 95+ degrees.

How hot is it In your attic when it is 95-100 outside?
What type of ventilation does it have?

I've had good success dropping attic temps 15-20 degrees in my customers homes by improving attic ventilation. Did one last week where the builder had installed ridge vents over felt and never cut the decking back properly. At 95 degrees outside attic temp dropped from 138 to 118 after opening it up.


Do you have soffit vents in the eaves?

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I'm in Cypress, so 95+ is a guarantee lol.

I've actually never checked the temp up there but I will when I get home today.

We have ridge vents and 2 pancake or mushroom vents. Also soffit vents, the thin plastic strip kind. The waves do have insulation stuffed down in them (discovered while trying to run Ethernet for security cameras) but have the inserts in them that's supposed to allow airflow....forget the name for the inserts.

Solar screens on any west facing windows. Amazing results

Solar screens, radiant barrier in the attic and adding several return air ducts in strategic places did a lot of good for my systems.

So it looks like I have 12 inches of R30 fiberglass.

Been raining here and overcast so attic only reads about 20 degrees warmer than house.

Quick video I shot....also shows the venting system installed on the eaves since I couldn't think of what they were called

fire09 said:

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Radiant barriers were probably the biggest improvement I made to my 2004 build. That said, I already had double pane windows and a well insulated attic.

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Did you do the spray on radiant barrier or the kind that looks like foil?

fire09 said:

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Radiant barriers were probably the biggest improvement I made to my 2004 build. That said, I already had double pane windows and a well insulated attic.

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Been interested in doing this myself. Sofit vents and ridge vents from 2004, insulation probably could use more as well.

The inserts are called rafter vents. Home Depot carries them near roofing and insulation materials. The come in a couple of widths for 16 or 24" framing. Raft-R-Mate is Owens Corning's product.

I stapled the mylar reinforced foil under the roof joists about 15 years ago. It made a big difference.

JP76 said:

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Blown in insulation is ~3.7 r value per inch so if you have 14 inches that should be okay. I like to see at least 11 inches if in an area where summers hit 95+ degrees.

How hot is it In your attic when it is 95-100 outside?
What type of ventilation does it have?

I've had good success dropping attic temps 15-20 degrees in my customers homes by improving attic ventilation. Did one last week where the builder had installed ridge vents over felt and never cut the decking back properly. At 95 degrees outside attic temp dropped from 138 to 118 after opening it up.



Do you have soffit vents in the eaves?

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I'll second air flow in the Attic, we had great insulation, great intake from soffits, but the air never moved (no turbines, just the flat vents). We put a solar exhaust fan in and it dropped the temp in the Attic a good bit...plus, and more importantly, it removed that oppresive stuffy feeling a 2nd story can get in the summer. It now feels fine keeping the AC at 77 most of the time during the day when the family is up there and 73 at night.

So i now fully believe proper air flow is just as important as the insulation.

Ikanizer said:

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I stapled the mylar reinforced foil under the roof joists about 15 years ago. It made a big difference.

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This seems very labor intensive

Do rafter vents allow for enough air flow from the eaves?

Good read on radiant barriers

Thank you for posting that! I was lurking on this thread and we may try that this fall. I am too old to install that until it is a lot cooler but I think it is doable. At least if my husband trusts me with the stapler.

Electric staple gun. It wasn't too bad. I'm a cheapskate. I remember when I was in the attic and I pulled the film over my head it felt like I was walking under a shade tree.

Radiant barrier is great, but if you're going to install it this time of the year get started early on a weekend and throw a sprinkler up on the roof before you start. You'll get an extra couple of hours of work in that way.

How do you decide on one type of radiant barrier over another? Seems to be several different kinds?

Solar screens, radiant barrier, and extra insulation were the three main things I did to help keep my house cool. The first year I was there, it had trouble keeping the house below 80 during the day. Once I did those three things, I keep it at 74 no problem. I used the radiant barrier from https://atticfoil.com/. It is labor intensive, but not as bad as you would think. My wife and I did our whole house (~1500 sf of attic space) over the course of several weekends. I would definitely not try to do it over the summer. We did it in November, and it wasn't bad up there at all. Also, do the radiant barrier before you insulate if you are planning on doing both. It will be much easier to get around the attic without all the extra insulation up there.

won't help you with a single story, but our master is over the west facing garage and can get hot in the summer. I put on some Owens garage insulation on the garage door and it's made a big difference in only a couple days.

My garage is detached with an open ceiling, so it would need a lot more than just radiant on the door to help it lol.

When applying in the attic, what do you do about rafter vents? Just cut around them and take the rest of t to the eaves?

I just covered up any roof vents with the radiant barrier material. The air flows in the air gap between the film and the underside of the roof up to the ridge vents. I focused on covering the under side of roof areas that take a direct hit from the sun - east, south and west facing. I have a pretty large area of roof that faces north and I only covered the parts that were easily accessible. LIke I said earlier I put the film on at least 15 years ago with an electric staple gun. I've re-stapled a couple of areas over the years. Definitely got my money back on this project.

Noticed yesterday (never paid attention) my garage has zero venting on the eaves, just about 20ftbof ridge vent across the top. Looked like I'll be changing that.

Also, should I be able to feel the air moving in the attic from the rafter vents?

I ask because when I was running Ethernet for security cameras last year, I felt no air, but when I pulled insulation out from the eave to run the wire, I instantly could feel a difference. Just want to make sure the basics like air flow are covered.