Insulatiing a screed porch enclosure

M

mrsrobinson

Well-Known Member
Mar 9, 2006
7,704
Virginia
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2001 380DA
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Caterpillar 3126
Demo and work started today on my 8 x 13 screen porch enclosure. It's going to be a 2nd office short term (until one of us retires). They will be using fiberglass in the walls and floor, which I am ok with. This is a lower budget build with me doing some of the work. I noticed the company that insulated my GFs fathers new garage used caulk between all the studs/joists/wood on the exterior walls. I was impressed, and doubt I will be getting that unless I pay extra or do it myself.

Is there value to caulking everywhere (exterior) before the drywall goes up? I watched them nail the 2 x 4's to the concrete floor for the exterior walls. Can/Should I add some caulk where the wood meets the concrete? If yes is there a special caulk for this?

Any other caulking/insulating tips and tricks I should do before they close it up?

Thanks
 
There is value to caulking the studs as well as the sill plate where it attaches to the concrete. How much, exactly? I dunno.

The purpose of insulation, at it's core, are 2 things:
  1. Stopping the thermal conduction; and
  2. Stopping the movement of air.
Point 1 is obvious. Thicker insulation (in general) means it's hard for heat to move between two areas. How does it do this? By trapping air in the insulating material. Air is an excellent insulator, when it's not moving. Think about that little gap between the glass of insulated windows; that little air gap provides a whole lot of R value.

Point 2 is a little less obvious. The best insulation doesn't work well if air is blowing by it. Again, air is a great insulation as long as it's not moving. If you have air gaps where a breeze can blow through the space will feel much colder/hotter that otherwise would be the case. This is why faced insulation has those paper tabs that stick out on each side - so it can be nailed to the studs and create a vapor barrier. This is also the purpose of house wrap like Tyvek.

Now to the point of the caulk. Sealing the studs and sill plate to the outer wall with caulk can dramatically reduce air leaks into the space, and thereby provide meaningful increase in warmth. What material to use? You want to use something that is very durable because you're only going to get one shot. I would use something like a PL construction adhesive, and don't skimp on it. Put on a big bead and get good coverage. This stuff isn't that expensive, and it's really going to help your climate control of the room.

A possible alternative to the caulk would be some expanding foam. Either use the professionally-applied stuff in lieu of the fiberglass batts, or the stuff in the can. Depending on the nature of your build both may be warranted, using the spray stuff for larger gaps/cracks.
 
mrsrobinson said:
Demo and work started today on my 8 x 13 screen porch enclosure. It's going to be a 2nd office short term (until one of us retires). They will be using fiberglass in the walls and floor, which I am ok with. This is a lower budget build with me doing some of the work. I noticed the company that insulated my GFs fathers new garage used caulk between all the studs/joists/wood on the exterior walls. I was impressed, and doubt I will be getting that unless I pay extra or do it myself.

Is there value to caulking everywhere (exterior) before the drywall goes up? I watched them nail the 2 x 4's to the concrete floor for the exterior walls. Can/Should I add some caulk where the wood meets the concrete? If yes is there a special caulk for this?

Any other caulking/insulating tips and tricks I should do before they close it up?

Thanks
Click to expand...
Cant help without pics.....you know the rules
 
b_arrington said:
There is value to caulking the studs as well as the sill plate where it attaches to the concrete. How much, exactly? I dunno.

The purpose of insulation, at it's core, are 2 things:
  1. Stopping the thermal conduction; and
  2. Stopping the movement of air.
Point 1 is obvious. Thicker insulation (in general) means it's hard for heat to move between two areas. How does it do this? By trapping air in the insulating material. Air is an excellent insulator, when it's not moving. Think about that little gap between the glass of insulated windows; that little air gap provides a whole lot of R value.

Point 2 is a little less obvious. The best insulation doesn't work well if air is blowing by it. Again, air is a great insulation as long as it's not moving. If you have air gaps where a breeze can blow through the space will feel much colder/hotter that otherwise would be the case. This is why faced insulation has those paper tabs that stick out on each side - so it can be nailed to the studs and create a vapor barrier. This is also the purpose of house wrap like Tyvek.

Now to the point of the caulk. Sealing the studs and sill plate to the outer wall with caulk can dramatically reduce air leaks into the space, and thereby provide meaningful increase in warmth. What material to use? You want to use something that is very durable because you're only going to get one shot. I would use something like a PL construction adhesive, and don't skimp on it. Put on a big bead and get good coverage. This stuff isn't that expensive, and it's really going to help your climate control of the room.

A possible alternative to the caulk would be some expanding foam. Either use the professionally-applied stuff in lieu of the fiberglass batts, or the stuff in the can. Depending on the nature of your build both may be warranted, using the spray stuff for larger gaps/cracks.
Click to expand...
Thanks, for clarity I wasn't referring to sealing the studs to the outer wall, rather in between the studs themselves, adding caulk between them, and then adding caulk after the fact around the sill plate where it meets the 2 x 4 and also at the top where it meets the top plate. And between the king stud and trim studs.

I was thinking about spray foam as well.

I will take some pics after the workers leave. I drew some circles around the areas I am referring to:

wall.jpg
 
Yes, caulk all that stuff. Especially the bottom sill plate. Those bricks are very uneven and you’ll get a shit ton of air through there. The idea is to stop air movement. Those small gaps between the studs will lot in a surprising anoint of air.
 
KevinC said:
Are they caulking to seal or possibly using construction adhesive to hold the studs together better ??

-Kevin
Click to expand...
I have not asked them but to the best of my knowledge they are not doing any caulking. Other than maybe cosmetic around trim work and such near the end of the project.
 
b_arrington said:
Yes, caulk all that stuff. Especially the bottom sill plate. Those bricks are very uneven and you’ll get a shit ton of air through there. The idea is to stop air movement. Those small gaps between the studs will lot in a surprising anoint of air.
Click to expand...
Exactly what I was thinking with the bricks and even at the top, this is an old porch/old house so I'm sure there's gaps and such.
 
Modern homes that are very tightly constructed use lots of caulk to make the building as air tight as possible. We recently built a new home that that is approximately 5,000 square feet in west Michigan along Lake Michigan. We get a lot of cold wind off the lake. Our gas bill in February was $149 and that included running our gas fireplace every day and heating a large garage to 55 degrees. Our electric bill runs about $110 a month and we make hot water with two large electric water heaters. So, keeping the cold air out is important to low utility costs. Caulk is an important part of the equation. Our previous house was half the size and had gas bills on the order of $400 in February.
 
We have a 12X22 screened porch. 2 yrs ago we wanted to see about enclosing it for all season use. I wound up having eisenglass panels made, like a lot of the outdoor bars around here are doing. They snap in and out, we heat it with a Mr Heater. This year we will install an AC/Heat unit.
 
It's only going to help, yes. But I would assume they're using house wrap and taping those properly? That's going to help with wind/air movement.

ABSOLUTELY use spray foam (minimal expanding) between the window/door frame and trim/jack studs. That is MUCH better than pushing some fiberglass batting in there.

I was going to mention moving up to 2x6's as that would allow for a substantial increase in R-value with more insulation... but then I saw that the project is already started :)

You might want to consider Rockwool batting insulation (mineral wool) rather than fiberglass - it's a better insulator and superior product in general with other benefits.

Side point... believe it or not, the studs themselves are NOT very good insulators. They're sort of a weak link in the system. Any chance they can put foamboard (or something like Comfortboard) on the outside before finishing? Probably not because the wall is already there so the extra thickness wasn't accounted for. It could still be done, though - even if the exterior wall is now proud of the floor. But that would offer a major increase in efficiency.
 
Yes, they are wrapping it. I see the roll next to the plywood. They did a house 2 blocks from here, that's how I found them, I was impressed with their work.

I read that recently, the studs themselves are not good insulators and people forget about that. 2 x 4s are standard here, I think 2 x 6s are mostly used more north for more insulation, right?

I got a really really good price on the work so I am trying to not be "that guy" and go behind them and ask for changes. I did upgrade to Anderson Windows.
 
Regarding 2x4... yes, they "have" been the standard (including up North)... in the past... and likely are still the most common. But I think times are changing and with more emphasis on efficiency 2x6' will be more and more common. Remember, it not only helps with keeping weather out... but also with keeping conditioned air in.

But, hey, that's a moot point at this juncture! :)

I hear 'ya on your last comment!
 
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