Need more and better insulation for upstairs
 

We need to insulate our new, old home better. Thankfully, the home was mostly insulated some time in the last 30 years by previous owners. We've got f/g bat insulation in the exterior walls. The upstairs is insulated pretty well (considering the house was originally built in the 1920s).

The floor joists for the 2nd floor are 2x6. The upstairs walls are 2x4. Most of the upstairs walls have a pretty decent covering of 3.5" R11 in between the studs. Most of the floor joists in the attic spaces in the 4 corners have 6" R19 (there's some pink, and some older cream colored. either the cream colored is now compressed or maybe it was originally 3.5"). In the very top of the roof area I assume it's probably more of the 6" R19. I can photograph it with my phone, but there's no access without cutting a hole in some drywall somewhere.

I want MORE, and I don't want to use the sprayed in crap if I don't have to. That might actually be a decent option for over the 2 bedrooms and the open space room since there's currently no human access to those spaces.

While it will be fairly easy to buy some fat rolls to lay out in the corners, I'm not sure how much good those will do if the walls are just a layer of drywall and 3.5" of R11. So I want to beef up the walls. WHat are my options that are relatively easy to DIY?

side view
http://forums.pelicanparts.com/uploa...1624928473.jpg

rough top view
http://forums.pelicanparts.com/uploa...1624928473.jpg

And a couple shots of what I'm working with.
http://forums.pelicanparts.com/uploa...1624928473.JPG
http://forums.pelicanparts.com/uploa...1624928473.JPG

above the 3 "rooms"
http://forums.pelicanparts.com/uploa...1624928473.JPG

I've wondered about some of the pink foam sheets, for the vertical walls on the outside of the studs, but I'm not sure if that will be adequate. Is there a way to attach more bat to those walls?

Any other recommendations? Would it make sense to pull out the old crap or just lay new stuff on top of it?

Spray foam.

An attic fan will help but rigid foam insulation is one of my fav. Simple to install. We cut with a table saw. 3" is plenty for us out here. Between joist, remove old (they aren't good anymore) and install new R 30-60. In the TX heat, your code may require more.

Great stuff. And you can get a special saw blade that is dust free specially for cutting the foam. Still wear a dust mask though.

We've got 2 whirlybirds and no soffit vents. I need to add soffit vents. My soffit is 3/4" shiplap on the second floor and 3/4" tongue and groove on the first floor. I hate to cut/drill into that stuff, but I need something to let air in to replace the air that's leaving out the top.

That's another thing, I haven't figured out exactly how I want to create soffit vents.

OK, so you think get rid of the existing and then use rigid foam, presumably for the vertical walls. What about the attic floor? Just deep rolls?

Yep, roll out new insulation. Check your building code. What you have there isn't enough. Ours are thinker then that. Stuff some of the rigid foam between the rafters may help. I raised the ceiling height and increased the pitch to create an open ceiling feel to this old house. Architect and I agree to use rigid foam, 3" in between rafters.

Cool, thx.

Is there power up there? Looks to me you have a vertical wall there? Cut a hold and install a gable power vent on one end and have a open vent on the other for cross flow. You can go fancy but I like the simple ones on a themoswitch. https://www.acinfinity.com/hvac-home-ventilation/shutter-exhaust-fans/airlift-t14-shutter-exhaust-ventilation-fan-14-temperature-and-humidity-controller/?gclid=Cj0KCQjw5uWGBhCTARIsAL70sLKpI7hCICsAYusRgE4 DFmgrqHR-Q0VBFEsf6q3EnDq2ulFb-Arq-ZoaAtWNEALw_wcB

If it were mine I would remove all existing insulation and start over . While everything is open fix your lack of ventilation . On your vertical 2x4 walls I would install fiberglass or rock wool and over that rigid foam with radiant barrier . That is the foam with the silver foil . If you can do the same to the ceiling do that . Radiant barrier works quite well in high heat areas.

The 2x6 floor rafters , while open fill/seal any openings like vent pipes/light fixtures etc you want to stop all leak paths . Then you can install new fiberglass insulation this can be rolls or blown in . Any box store will rent you a blower for the fiberglass and sell you the bags of insulation . While messy it is a DIY project . I don't like the way it settles but I think it's the best bang for the buck .

Your walls are "okay". I'd focus on the ceiling.
If you really want to beef up the walls spray foam is the way to go. The ceiling you just add more batts.

Unfortunately, I don't think there's anywhere to put a gable. Normally, we could put one above the windows in the dormers, right?
Unfortunately, the only vertical walls on the second floor would go directly into one of the rooms.
http://forums.pelicanparts.com/uploa...1624968417.jpg

I've been wondering about some sort of radiant barrier. And I feel like I need something more for the walls since they are exposed to the attic which is a giant hot box. Our old home had blown in insulation. It was horrible. I'm not a fan. I'm much more likely to use rolls.
thanks. Since the entire second floor is surrounded by attic, and the attic gets hot, I feel like the whole thing needs more. I've seen someone on here talk about having 24" of insulation in their attic. In my case, if I want that route, what would be the point in having something like R75-R80 on the horizontal surfaces and then only having 3.5" of R11 on the walls. So far this year, we've been lucky with cooler than normal temps, but before too long it's going to be July and Aug and then it's going to suck.

You can make your 2x4 walls into 2x6 or more by scabbing on additional wood to existing studs .

1. You have to add/increase your attic ventilation . Without it you are fighting an uphill battle .
2. If you add soffit vents and a ridge vent you can add radiant barrier to the roof structure . As an example if your roof trusses are 2x4 stapling radiant barrier creates 3 1/2" troughs for the cool air ( relatively ) to enter the soffit and exit the ridge . The barrier also radiates some heat away from the attic space .
3. Can't stress enough about sealing all leak paths . Any leak path allows heat/AC to escape and be replaced by what you are trying to " condition " against .

Your walls are probably "average" but your ceilings are way below average based on the pics.

If you can match the shingles close you could remove the ridge cap and have ridge vent installed to help with ventilation. You'd have to remove the cap, cut the roof about 1.5" to each side of center to provide air gap, then install ridge vent and then the ridge cap. Probably not the most cost effective way of going about it but an option.

Right, I get it. The house stays remarkably cool and comfy without the AC having to run constantly (which is a pleasant surprise), but I think the house has a lot of leaks. Hell, I know that I can see light under the front door and around the side door. I need to get those two spots sealed off for sure. The missus wants to seal up the side door and replace it with a window. (there's a second side door that we would use) So I guess that's got that door covered. The Front door is going to require a little repair of the threshold.

The "good" news is that a new roof is in our future. And usually a hip roof isn't a good place to install a ridge vent, but since we have the east/west facing dormers, we actually have a nice long ridge to work with. I'll probably wait and let the pros install the ridge vent when we get a new roof (probably within 1-1.5 years) at most.

PIR insulation boards

They give double the insulation value per thickness than fibreglass rockwool rolled out insulation

https://www.panelsell.co.uk/cavity-insulation-value-comparison

If you're fitting a new roof then it would be a lot easier to do the new insulation then

May I ask what's the hate towards spray foam insulation.

This is what I was going to do to my house

You got me wondering

We have no soffits to add vents in.
So I had something like this added

https://m.youtube.com/watch?v=sUaYv-cGxro


https://m.youtube.com/watch?v=JMdaGiRnog8


combined with the existing ridge vent it definitely helped cool the attic

From a certain point of view, I'd love spray foam. When done right, I suspect it's the most efficient insulation available at a reasonable price.

From my point of view, spray foam is like a started that's installed under the intake manifold of a V-engine. It's great when it works, but then if you've got to get into the walls to do any electrical or plumbing or any work on drywall, I assume it's a nightmare. And for me at least, since this home is 100 years old and likely to require maintenance on all sort of things, I don't want to make it difficult for myself.

I think that if you were building a new home, it might be great. You'd probably want all electrical or other sorts of cabling installed in conduits and plenty of conduit available in case you ever want to install other stuff. If I were building a new home, I'd wonder about lining walls with plastic or something so the foam isn't actually gluing the entire house together (again, making the inevitable maintenance a nightmare).

But I've never dealt with spray foam, so maybe I'm completely off base. I'm doing a lot of ASSuMEing. (misspelling intentional)

Do they do blown insulation in Texas? That's the way we insulate from cold in the north.

Absolutely. Is insulating against extreme cold different from insulating against extreme heat?

It's all about heat transfer.

Right, the only difference between here and up north is the direction of the transfer.

All good suggestions, plus I would beg rent or borrow an IR camera.....

Would you recommend an air barrier if used on original 2x8 T&G beamed ceiling/roof? Currently don't have any insulation on our main roof section of the house. Originally built as an un-insulated beach house and then insulation was blown in later.

We've been considering adding additional rafters to our original beamed ceiling, insulating and then sheet rocking. I was originally thinking of the spray foam but, like the idea of the rigid, less mess and I could do all that myself.

SAT

Most people misunderstand how to cool an attic. Its air movement that's the most important not just thick or effective insulation.

How will rafter be added? Cutting a hold on the side and shove it in from the inside? Sounds like this will be a finished living space or storage? Why do you want to add thickness to rafters? Just to house insulation?

I've got one.

Ridge vent when you do the roof.

Absolutely!

Check out my Man Cave Thread, I've been doing a lot of insulating between rafters

Using 2 layers of 3" board, I bought a insulating board saw but found an old wood saw much easier. All my sheets are a tight fit between the rafters and I also aluminium foil tapped all the joints too

It does make a bit of mess but it's a clean mess so can be swept or vacuumed up easily

It a very easy DIY job

I don't have attic in the main section of the house. The whole south facing part of the house (Living/Kitchen/Dining) is built with lam ridge beam, 4x6 rafters on approx. 6' cntrs and 2x8 T&G planks.

http://forums.pelicanparts.com/uploa...1625069594.jpg

Adding additional rafters for two reasons, one being nailers for rocking the ceiling and two, create smaller cavities for the spray in foam to hold (if I go with spray). What you see is my roof. No insulation under the composite shingles up top. Was originally considering spray foam to mitigate condensation since there is no ridge vent and I don't have sofitts. Insulating up top would require additional rafters anyway to support the additional weight of insulation and then sheathing on top of that for the roofing material.

My question is whether the rigid foam could be used as an alternative to the spray in. Would the rigid foam induce condensation and then mold because it's not completely flush with the T&G?

Same, just a question of whether or not the blowing machines are available to rent. I wouldn't haul it into the attic, but blowing it in is easy.

This is very interesting. If I understand you correctly, your roof/ceiling is
shingle
decking (usually plywood)
TnG boards
rafters

I'd absolutely want some insulation up there! By comparison, my shoddily installed, old insulation is fantastic.

The 2x8 T&G is the decking. No additional sheathing up there. Built in '61 and the roofing material was originally tar and volcanic rock with french drains. We removed that, trimmed the fascias down and installed a traditional shingle roof with gutters.

We're right on the coast and through the majority of the year, our temps are great, coastal breezes used to cool the house (no AC). It's those rare occasional days in the high 80s/low 90s (minimal wind) that make me want to mitigate the heat from the roof. The section of the house with the bedrooms and baths are traditional sheathed rafter with attic space. I have eave vents and roof vents there though the insulation needs to be replaced.. It's blown in cellulose that was probably done in the '70s. Being the North facing, the heat there has never been an issue really though replacing that insulation would help. Shallow pitch and I'd have to open a ceiling to get up there.

Wow, very interesting!

Poor man's Eichler:D

The house is L-shaped and the interior of the 'L' is a flat roofed carport with the same planking. We did torch down there. The whole carport is big beam open construction. I love the look though and have been struggling with covering it up. The other advantage of rocking the ceiling aside from insulating is being able to add can lighting. Currently running track.

SAT, have you considered adding insulation above the deck, then roof over it, non vented assembly. I did my house with this method, works quite well with low slope steel roof.

Yep, back when we converted the roof to traditional shingle. We also toyed with going to a steel roof as well (love the look). In either case, I'd have to add additional rafters to distribute the additional weight.

The R rating back then wasn't very good either.. What R did you end up with?

Hogging Masraum's thread. Really do not know why they would need additional rafters, standing seam metal with foam and Z mounts does not weigh much. I have that configuration over the garage with 2.5" polyiso about R15, and in yesterdays 100 deg heat direct sunshine on roof it was 77 in there, no ventilation and little insulation on the main door, that is probably where most of the heat transferred in over the last couple of days, but the entire surface above deck is foam, no joists for thermal transfer. Most of the nearby houses were way hotter then my garage.

No worries, more information floating around is generally better than less.