Insulating Shop 30 Years Later

[JoeLee1]

I know..... why didn't I insulate it when it was built. Well, back in the mid 80's heat bills weren't too bad.

The building is 8" block. It's next to impossible to try to insulate the walls on the inside with all the electrical conduit, switch and outlet boxes and air lines that are all over all the walls.
Cabinets, work benches and stairs that are lagged to the walls etc. Way too much work to try and remove all that now.

So, my only option at this point seems to be to insulate the walls on the outside. There's a local company here that does brick face. They tack 2" foam sheets to the walls, tack the wire mesh to that and then spray the mortar on and finish it.

But there's problems with this as well. First off how do you start the wall at the ground ? There's no brick ledge on the footer to start a new wall on.
You can't start it at ground level because the ground heaves in the winter and will crush the perimeter of the wall at the ground level.
How would you end the wall at the top where it meets they vinyl siding on the gable ends ? It would be sticking out probably 3" past the siding.
Well, the siding could be removed and the brick face continued up to the soffit, but then the soffit would have to be removed so the brick face could
continue up behind it and then the J channel and soffit reinstalled.

There are still other questions but these are the biggest issues that I can think of.

The ceiling has 6" between the rafters. I could add more insulation but the big heat loss problem is the walls.

Any thoughts??

Joe......

 

[billconner]

I would think a shelf angle several inches above the ground and don't worry about 3 or 4 inches. Then Z flashing at top of new foam on gable walls. Bit if a bird perch maybe.

Don't know what foundation is but the exterior foam and stucco could continue below grade perhaps. What's your climate?

 

[rancherbill]

I know..... why didn't I insulate it when it was built. Well, back in the mid 80's heat bills weren't too bad.

The building is 8" block. It's next to impossible to try to insulate the walls on the inside with all the electrical conduit, switch and outlet boxes and air lines that are all over all the walls.
Cabinets, work benches and stairs that are lagged to the walls etc. Way too much work to try and remove all that now.

You can inject foam into the block wall via hole drilled into them.

So, my only option at this point seems to be to insulate the walls on the outside. There's a local company here that does brick face. They tack 2" foam sheets to the walls, tack the wire mesh to that and then spray the mortar on and finish it.

But there's problems with this as well. First off how do you start the wall at the ground ? There's no brick ledge on the footer to start a new wall on.
You can't start it at ground level because the ground heaves in the winter and will crush the perimeter of the wall at the ground level.

If the ground is heaving your building is heaving, UNLESS, the wall is on footer below the frost line. Rigid foam and mortar have to be on a solid building.

How would you end the wall at the top where it meets they vinyl siding on the gable ends ? It would be sticking out probably 3" past the siding. Well, the siding could be removed and the brick face continued up to the soffit, but then the soffit would have to be removed so the brick face could continue up behind it and then the J channel and soffit reinstalled.

That's how to do it.

 

[billconner]

You say brick face but also foam and and mesh and mortar. So it's foam and stucco with bricks molded into it?

 

[JoeLee1]

I would think a shelf angle several inches above the ground and don't worry about 3 or 4 inches. Then Z flashing at top of new foam on gable walls. Bit if a bird perch maybe.

Don't know what foundation is but the exterior foam and stucco could continue below grade perhaps. What's your climate?

I never thought about starting the wall a few inches above the ground. I don't know how that would work with snow. Terminating the top with the Z channel or bending a piece of aluminum at an angle would be a better approach as the birds wouldn't be able to perch on it.

The foundation is poured concrete 4 ft. deep.

Joe.....

 

[JoeLee1]

You can inject foam into the block wall via hole drilled into them.

If the ground is heaving your building is heaving, UNLESS, the wall is on footer below the frost line. Rigid foam and mortar have to be on a solid building.

That's how to do it.

Trying to inject foam into the cores of the block is worthless with the amount of mortar that squeezes out and blocks the cores.
I did pour zonalite down the walls before I bolted the plate down but that stuff settles out over the years and has like an R3 value.
The building isn't heaving, the foundation is 4 ft. deep.

Joe......

 

[JoeLee1]

You say brick face but also foam and and mesh and mortar. So it's foam and stucco with bricks molded into it?

Yes, I've seen it done both ways. Some scribe out the mortar joints using a straight edge as a guide to make it look like brick and some set in thin pieces of brick to the mortar after they spray it. Scribing or scratching out the joints is probably the faster way to do it.

They put down 2" foam sheets and mesh with both methods.

Joe.....

 

[The Cobbler]

You can inject foam into the block wall via hole drilled into them.

would be negligible r value at best . the thermal bridging from the cores is probably the largest culprit as air is actually a pretty good insulator . also the cores are probably a good part full of mortar and it would be tough getting them full of foam with no voids

 

[Jacko264]

be very careful some houses I have seen get damp in them after having insulation on the out side as you described
this is i the uk

 

[billconner]

Look up EFIS - exterior insulation finishing system. Not much different than what you described, but perhaps less expensive. It's on a lot of lower budget commercial buildings - strip malls and such. Basically foam, mesh, and an acrylic compound. Doesn't take abuse well - shopping cats, lawn mowers, kids that like to poke into things. Just a thought. It sounds the tradesman you spoke to was going it the very best way with metal mesh and a concrete based mortar.

Still wonder if it can't go into ground, just like ICF. Would need a different coating below grade, but would help keep building warmer with less energy.

As far as gables, did you consider stripping vinyl and just continuing foam and mud all the way?

 

[JoeLee1]

would be negligible r value at best . the thermal bridging from the cores is probably the largest culprit as air is actually a pretty good insulator . also the cores are probably a good part full of mortar and it would be tough getting them full of foam with no voids

Yes, the thermal bridging or lack of a thermal break in the block wall is the largest culprit as you say. That's why trying to spray or inject foam into the cores is just a waste of time and money.

Joe...

 

[JoeLee1]

be very careful some houses I have seen get damp in them after having insulation on the out side as you described
this is i the uk

Interesting, the only reason for that happening that I can think of is the house is now sealed up so tight that it doesn't breathe. Running a dehumidifier inside would probably help.
I have to say that I'm very fortunate because nothing in my shop rusts. During the summer I run a dehumidifier keep the humidity around 40%, during the cooler months in winter the heat is running and the humidity is even lower probably like 20%.
This leads me to another question... Would 2 inches of foam insulation be equally efficient on the outside of the wall as it would be on the inside ??

Joe....

 

[JoeLee1]

Look up EFIS - exterior insulation finishing system. Not much different than what you described, but perhaps less expensive. It's on a lot of lower budget commercial buildings - strip malls and such. Basically foam, mesh, and an acrylic compound. Doesn't take abuse well - shopping cats, lawn mowers, kids that like to poke into things. Just a thought. It sounds the tradesman you spoke to was going it the very best way with metal mesh and a concrete based mortar.

Still wonder if it can't go into ground, just like ICF. Would need a different coating below grade, but would help keep building warmer with less energy.

As far as gables, did you consider stripping vinyl and just continuing foam and mud all the way?

The two processes that I mentioned previously are just as susceptible to damage as the process that you just mentioned.
I've seen a few buildings that this local contractor has done, they look real nice but the exterior is very delicate. Corners that have been bumped and crushed, as well as sections at ground level from heaving.
I did mention in a previous post about removing the vinyl on the gabled ends and running the brick face right up to the roof line. But all the soffit and j channel would have to be removed in order to run the wall up behind it.

Joe....

 

[billconner]

I don't know if inside or outside is better. Instinct says thermal mass inside but I don't really know. If you did do inside, one of those basement systems with vinyl channels for attaching drywall or ply would seem good. But when I think of that surface conduit, etc., I'd run away from that. Yuck.

 

[MichaelP]

In this particular situation I'd just insulate attic well, make sure it's properly ventilated, check and correct major air leaks around doors and windows and be done with the project.

But to satisfy OCD, a thermal insulated interior paint can be used. I never tried it personally and cannot say if it really makes any noticable difference, but, theoretically, it can make some improvement if applied correctly following manufacturer's recommendation (three coats, IIRC). Whether it's worth it is up to you to decide.

 

[Bert_]

Don't know what your temperature is like or what the heat cost is but if the building is well sealed and the attic insulated you have to wonder if you would be farther ahead to just pay the bill.

Makes a difference how old you are too.

 

[hefnerconstructionlc]

I agree with Bert, make sure all the low hanging fruit is done. Air seal all cracks. Fully insulated attic 45% of your heat loss right there. Insulated doors with good seals.

 

[jshillin]

This may not have as much R value as what you were looking at, but this would be easier. Why not attach foam insulation boards to the block, then go with furring strips and cover with vinyl siding? It would give you a finished look and you can control where you start it so it's not on the ground.

 

[billconner]

I would think vinyl siding would be more expensive than stucco - either concrete or acrylic - but an interesting option. Buy the foam for basement walks with furring strips built in.

But, it did suggest an option - insulated vinyl siding. Only an r value of 2 to 4 but maybe enough and a good fit.