shabbey road construction advice please

[xSpace]

We are still on topic since insulation is going to be part of the project.

The issue is simple. You cannot place a vapor barrier in the middle of a double wall assembly. Period, it will not work.

A Class 1 vapor retarder is aluminum
A Class 2 vapor retarder is 4 mill poly plastic sheeting

The difference is the perm rating of the materials and the cost. There was a time when aluminum clad panels where used to sheath homes as the design called for.

So if you spray urethane on the interior side of this room then that is your vapor barrier and you have to close that air space. You cannot install an interior separately framed and insulated wall and expect the results to be good, they will not. Heaven forbid that after this urethane is installed that some lose cannon places ploy on the interior side of the newly framed assembly (creating a double barrier).


I agree that as it applies to the thermal environment urethane is the go to product, what I do not agree with is for any one, myself included, is to say "do this or do that" and not be able to have everything needed to access the structure and to complete the job to the end in such a way as to not promote problems.

After the first 7 pages of the pdf file you linked to, the author(s) say this:

"Critical Takeaways
...
In cases when an exterior retrofit is not possible, it should be noted that adding interior insulation
to the walls of masonry buildings in cold (and particularly cold and wet) climates may cause
performance and durability problems, particularly rot and freeze-thaw."

So we know that this is not part of acoustics.

This is part of an existing aspect to how the elements interact with building materials and is now a growing concern for a better thermal environment aided by physics. And these elements can not be man handled or treated lightly as you can literally destroy a structure and/or make people sick if the implementation is handled blindly.

[Cold]

Brien,

You are correct, I was wrong to use an open ended, all encompassing statement.

I will happily rescind the statement " In our climate all concrete or brick type walls are sprayed with 2lb closed cell foam"

Is the below more suitable?

In our climate, exterior concrete or brick walls are often sprayed with 2lb closed cell foam, especially commercial and multi residential buildings and frequently detached homes. This foam is applied as both exterior and interior systems. It is used as both the sole form of insulation within a wall system, and also used, in conjunction with other insulation types, as part of an insulation system.

Most importantly, always do your due diligence and research as to whether or not a wall system incorporating foam ( or any wall system for that matter) is the appropriate and best code approved solution for your area.


And I will add the caveat that closed cell foam is not exceptionally useful either for isolation or treatment. For many wall systems there are better options, as pertains to a studio build.

The specific pages of the document that I found pertinent were 20 through 25.

This shows 1 system that incorporates both closed cell foam and fibreglass batt.



Quote from Brien :
"The issue is simple. You cannot place a vapor barrier in the middle of a double wall assembly. Period, it will not work."

And this is the heart of the matter. What is the best wall assembly to use for a double wall system, where the exterior wall is brick?

As an aside, what is best practice for a double wall assembly when the exterior wall is metal, such as in a metal building?
Leave this one for the moment, we'll perhaps explore it in a different thread.




I will do some more research, as I can't recall ever seeing a tested, exterior, double wall assembly with the exterior wall being brick or concrete.


Do you know of any tested examples?

Steve

Ps I work as an insulator, so i truly do care about this stuff, but I am not an hvac engineer.

[xSpace]

I am going to PM you over the next few days Steve, and we can pick each others brains since we are now really getting off topic...but it is a topic that I spend much time on just because it has so many schools of thought.

Thank you for what you do...that means a lot to me...as you understand this a multiple craft operation and not a one size fits all...

[shabby road]

Thankyou gentlemen for all your attention so far. I am hanging on doing anything to the studio until the issue of potential condensation and approach for insulation in my circumstances are resolved.

And this is the heart of the matter. What is the best wall assembly to use for a double wall system, where the exterior wall is brick?

You all seem to be in agreement about foam spraying the roof to seal and protect it. I could foam spray the inner walls too but thats means I'm going to lose a lot of internal space needed for the construction the seperate inner studio walls.
Would it be too simplistic to seal the outside concrete block work with a waterproof paint or fabric to stop moisture penetrating through to the inner wall?
A basic line drawing of what you consider the best way forward for my situation from outer skin of the building to the inner studio wall would be most useful.

Thanks

Tim

[jdh]

I'm following this thread with interest as I have a building of very similar construction that I am planning to soundproof (eventually). Mine is also built from concrete blocks which I intend to timber clad on the outside.

I'm planning to fix 1" battens to the outside and fit 25mm rigid foam insulation (kingspan) in between the battens. I'll then add a breather membrane before nailing the cladding to battens. This should prevent moisture getting to the concrete blocks, ensure that the cladding doesn't constitute an additional leaf and provide some valuable insulation. Thanks to Rod Gervais for this suggestion.

[shabby road]

Hi jdh

Thanks for your reply It's good to know I'm not the only one in this situation.

I'm planning to fix 1" battens to the outside and fit 25mm rigid foam insulation (kingspan) in between the battens. I'll then add a breather membrane before nailing the cladding to battens. This should prevent moisture getting to the concrete blocks, ensure that the cladding doesn't constitute an additional leaf and provide some valuable insulation. Thanks to Rod Gervais for this suggestion.

Did you get the info above from one of rods books? i have "build it like a pro" can't seem to find anything about it in there.

Cheers

Tim

[xSpace]

I'm following this thread with interest as I have a building of very similar construction that I am planning to soundproof (eventually). Mine is also built from concrete blocks which I intend to timber clad on the outside.

I'm planning to fix 1" battens to the outside and fit 25mm rigid foam insulation (kingspan) in between the battens. I'll then add a breather membrane before nailing the cladding to battens. This should prevent moisture getting to the concrete blocks, ensure that the cladding doesn't constitute an additional leaf and provide some valuable insulation. Thanks to Rod Gervais for this suggestion.

When Rod supports this, we may (some of you) put it to rest as it applies to you Mister new poster.

What you are suggesting is thermal.

[Soundman2020]

I'm planning to fix 1" battens to the outside and fit 25mm rigid foam insulation (kingspan) in between the battens. I'll then add a breather membrane before nailing the cladding to battens. This should prevent moisture getting to the concrete blocks, ensure that the cladding doesn't constitute an additional leaf and provide some valuable insulation. Thanks to Rod Gervais for this suggestion.

Rod suggested that? Is that in his book, or on one of the forums he posts on, or in private correspondence? I'm rather surprised that he would suggest such a thing. It certainly doesn't seem to fit in with what he normally recommends.

Can you provide a link to where he said that?


- Stuart -

[shabby road]

Just to try and consolidate all the valuable info offered how about this as a solution?

timber cladding/concrete blocks/air gap/independant stud wall with insulation/ vapour barrier / 2 x layers of drywall

It avoids sealing the concrete blockwork which hopefully allows it to breathe so any moisture and condensation present on either side of the concrete will not be trapped. The vapour barrier would be installed on the internal indepedent stud wall in between the studwork and 2 x layers of drywall. (see diagram below)

[Roguejackal]

I'm following this thread with interest as I have a building of very similar construction that I am planning to soundproof (eventually). Mine is also built from concrete blocks which I intend to timber clad on the outside.

I'm planning to fix 1" battens to the outside and fit 25mm rigid foam insulation (kingspan) in between the battens. I'll then add a breather membrane before nailing the cladding to battens. This should prevent moisture getting to the concrete blocks, ensure that the cladding doesn't constitute an additional leaf and provide some valuable insulation. Thanks to Rod Gervais for this suggestion.

2nd that, I am doing the same with my build, outside skin is concrete block and some will be rendered, some will be battens 30mm kingspan and breather membrane with timber cladding.
This a method used frequently on houses and buildings in the UK.

[jdh]

Rod made the suggestion in response to my post on this site (didn't realise it was that long ago), see link below.

The primary reason for this approach is aesthetic and to provide some protection for the blockwork. I realise that this will give me thermal insulation rather than sound insulation.

http://www.johnlsayers.com/phpBB2/viewt ... 5&start=15

[Soundman2020]

see link below.

Ummm.... That link leads back to this same thread!

- Stuart -

[jdh]

it's been a long day, try this link:

http://www.johnlsayers.com/phpBB2/viewt ... 01#p103001

[Cold]

I am happy to see this thread is still going.

Tim,
Quick question, how much space do you have around the outside of you building.Do you have room for thermal insulation on the exterior? I assumed you didn't from the posted pictures and that may have been a faulty assumption.

I asked about your situation over at a different site

http://www.sprayfoam.com/mnps/fullthrea ... &startat=1

And didn't think the solution would be optimal for your situation.

I'm still pursuing some other research at the moment, just not a lot of time right now.

Brien, I appreciate the fact you keep me honest.

Roguejackal,

Can you post any more info on your system? Thanks.

Steve

[xSpace]

I'm following this thread with interest as I have a building of very similar construction that I am planning to soundproof (eventually). Mine is also built from concrete blocks which I intend to timber clad on the outside.

I think the two projects are 180 degrees apart. This current project is trying to find a way to insulate the interior...yours seems to have already settled on the exterior.

I agree that a thermal envelop can be produced on the exterior side, but I would have to have more information, elevations, what is at ground level, what part of the structure goes underground, is a french drain a requirement, etc.

With no more information about how the inside was/is handled you have to know a few things. Typical procedure is "warm-side-to-the-cold-side" as it pertains to a wall assembly...and the perm rating of the materials involved to produce a healthy assembly.

Extruded polystyrene / Expanded polystyrene has a perm rating of (depending on many factors) .4 to 1.6 and 2.0 5.8 respectively.

That said, walls that use this approach should not use an interior vapor barrier or vinyl wall paper since this constitutes a double barrier. This is information that was left unsaid and is of much important, not that it was done intentionally, but often these threads move fast and as often look the same, for whatever that is worth