I am considering isolating an apartment wall that yield to the outside from the cold. The wall which is a bedroom is made of solid brick (no isolating airwall) and easily looses heat to the outside. An additional problem I have is that condensation easily build on the cold wall surface and as a result have problems with humidity and mildew.
To solve the problem, I would like to panel the entire room in wood (wood is for aesthetics not just to solve the isolation problem) and for the wall yielding to the outside, put a layer of rockwool under the panel for further isolation from the outside.
My question are: 1. Is the idea feasible - i.e. are the any problem with using rockwool embeded in the wood paneling ? 2. How does rockwool fare with potential humidity buildup on the cold wall with which it is in contact ? 3. Would it be a good idea to sheet the rockwool in the panel with impermeable material eg. plastic or other within the wall to avoid rockwool dust buildup or transmission into the house ?
Thanks for your comments, Tuka ************************************************************** 11-22-05, 06:46 AM Walks On Water First, welcome to the pool. We may not have all your answer, but it will give you a good place to start.
Now on to your questions. If it is cold enough that you need insulation, then you need at least 4” (103mm). I don’t believe rockwool is used anymore now it is fiberglass. Don’t get me wrong, any amount of insulation will help.
Next, no matter how thick your insulation is, you must install a vapor barrier between your living space and the insulation to block humidity from getting in to the insulation and getting trapped there. Not only will the cause you to loose insulation efficiency but the moisture will cause rot and mildew in the walls.
In the USA, you would build a 2 X 4 stud wall, insulate, tack on a vapor barrier such as plastic sheeting material, then hang the drywall (plaster board) or paneling.
Hope this helps. I am sure you well get more information from other contributors.
11-22-05, 10:21 AM Tuka I have been doing a little bit of research and it does seem that fibreglass is more used (at least in the US where most of my sources are..) Since I live in Portugal, Europe construction here seem to use more rockwool (although I have not deeply researched).
Temperature here can become -1 degrees centigrade at record low temp temperature (that is 1 degree below freezing point - dont know the equivalent in degrees F).
11-22-05, 10:42 AM frankvan Welcome to the 'pool, Tuka. -1 deg Celsius would be 30.2 deg Fahrenheit. F = 9/5C +32. We are probably the only civilized nation that clings to the Fahrenheit scale and resist the metric system in general. Go figure! Confused
11-22-05, 02:59 PM DvdGStwrt Yes, Vapor barrier is needed. The material you are talking about does hold up to moisture rather well but it also traps moisture. I used it to re-skirt our trailer – however cutting/drilling the material wears out the bits and blades rather fast. Then attaching it to the brick will be problematic, any glue or adhesive will, over time, come loose. The brick will suffer the wages of time, thermal expansion and contraction and will slowly crumble under the adhesive.
An alternative: You could build a 2x2 frame with uprights (studs) set every 16 inches Since it is not a load bearing wall you are building – you are more or less building a partition. There are foam insulation panels sold rather inexpensively at home stores. Some of them come in 4x8 panels; others come in between the stud sizes. Use that to fill the spaces between your 2x2 studs. Why 2x2? Because one inch of foam panel has a higher R value than 2 inches of fiberglass – besides fiberglass is really messy to work with, and can lead to inhaling glass, getting glass into the skin (itches badly) and I the eyes and all of that. Unless you have the tools and have worked with fiberglass insulation before.
The foam is also clad with a vapor barrier. This would provide you with a nailing surface for your paneling – might also be able to go with dry wall (cheaper in the long run than paneling) The partition wall would have to be anchored to the floor, meeting walls and ceiling.
For any widows you would have to build out the sill/frame. There are electric box extensions which mean you won’t have to move the electric boxes, these are usually plastic, mount onto the existing electric box, and then you reinstall the outlet/switch.
Granted an inch or two of foam will not result in a great insulation value, but would be higher than just the rock wool paneling.
If the foam is too much, then set the 2x2 frame about 1 inch from the brick wall (air space behind the frame) and vent at the floor and the ceiling every 8 feet – this will give you a dead air space which will have some insulation value to it, but will also allow air flow to let the space behind breath – venting out any moisture.
With this you would need to move electric boxes. I’m assuming that either there is exposed conduit, or no electric on that wall.
11-23-05, 06:17 AM Tuka Thanks for the great input, DvdGStwrt and all..
I do have a few questions... Since I am newbie to bricolage, I am not familiar with some terms:
2x2 - does this mean the crossectional width x height of the wood to use in building the frame i.e 2" by 2" ?
The FOAM - The foam you mention, is this styrofoam based or some other type of foam ? if you could give me the technical specs or include a link to some internet site that shows an example I can glean specs from, that would be great.
The VENTING - is this venting to the outside ? what would roughly be the dimentions of a decent vent (can be in inches..) ? Any precaustion to take on a vent ? I guess a gauze would be sufficient to avoid insects and the like...
Thanks again..
11-23-05, 02:27 PM DvdGStwrt 2 x 2 means that the lumber is 2 inches wide by 2 inches thick - usually measured in feet in length. As 2 x 4 is 2 inches thick by 4 inches wide.
However we no longer make them actually 2 inches by 2 inches or 2 inches by 4 inches.
I’m talking about the Styrofoam Panels (cheapest) they sell at Home Depot and Lowe’s in the insulation department, they come in 4 x8 feet panels and I believe either 2 feet x 8 feet or 16 inches by 8 feet panels. Easy to cut (although if you ever cut styro you know how messy it can be). Most likely you will need to tape them flush with your frame since they will not be the same thickness as the frame. Grey tape (gaffers, duct, navy, etc tape) works well.
Venting, or ventilation in this case means into the room, inside. All you want to do is insure that there is a way for air to flow in and out of the space behind your wall to extract moisture from the brick so it won’t build up and lead to mold, mildew or rot. You don’t need large openings in this case. You could get away with a 1” hole at the top and at the bottom of the wall set every 8’ – however having holes in the wall would look tacky, so you would want to get a nice vent cover.
11-24-05, 08:39 AM Tuka Thanks again for your reply and your help here...
I do have one question about styrofoam - I have heard that styrofoam is to be used only where it can be fire-proofed. Upon careful reading, I see that the panels you included in you link is a self extinguishing sort of styrofoam (first time I hear of it). I include a quote from the manufacturer specs..
quote: If a fire breaks out, this item is safer because of its self-extinguishment.
Is this the case generally with insulation styrofoam ?
Also regarding venting to the inside.. I would like a clarification. The inside of my apartment, tends to accumulate humidity overnight from breathing/cooking/hot showers etc... and this humidity condences on the wall especially under the window of the rooms where it is cool. (I can of course reduce the cooking and shower humidity by forced venting but that would not solve humidity from breathing).
If I now put vents on the inside, won't I then permit inside humidity from getting to that cold wall and condensing there ? Also wouldn't there be a problem of some cold air from the section between the wall and partition coming into the living space reducing the effect off insulation ? Or would the potential draft be negligible ?
Cheers, Tuka
11-25-05, 08:47 AM aminator2002 In building a wall in front of a brick wall the most critical aspect is an air space. This prevents the moisture from the brick wall from tranferring to the insulation and also provides some insulation just from the air. It is especially important to hold all insulation away from a brick wall. Even with foam products you can attach small holdaways into the brick wall (sometimes called baffles). Typically the airspace is 1". The only time airspace isn't used is when solid fill insulation like sprayed in rock wool or composite materials are used.
I also have never heard of venting an interior wall... especially when a vapor barrier is being used. You typically want to make sure that all surfaces are 100% sealed to the inside when using a vapor barrier because any weak point becomes a point of condensation. Maybe you can clarify David.
Rock wool is as good as anything and I think that if it's readily available that you should use it... working with the foam panels can be more difficult. I think just putting up a framed wall in front of the brick and only attached to the brick using tie backs and then insulating the frame with rock wool and paneling over it.
Do builders typically use vapor barriers in Portugal? Do you use air conditioning in the summer? It doesn't seem that necessary to me, but I live in a much different climate where vapor barriers are a must.
Your question about the foam... Foam has an unacceptable flame spread to be left unprotected. This just means that you have to cover it with a material that doesn't have a high flame spread. This is typically accomplished using drywall but it shouldn't be a problem to cover it with paneling. Again... if rock wool is used in your neck of the woods then probably easiest to use rock wool.
Also, I think primarily what you are trying to accomplish is draft stopping so you should make sure to insulate very well around windows. There are spray foam products that you should spray into any holes or open joints in the wall before you cover it with the paneling.
11-25-05, 09:57 AM Tuka Thanks aminator2002,
Your answer seems to confirm some of my thoughts although I would like to hear from David. We'll see.
Historically insulation was not used in Portugal as you have 4 cold months (and by that I mean the 0-10 degree centigrade range). Only lately has new construction been including walls with airgaps (doublewalls) and insulating materials but based on my observations any contruction more than 10 yrs old does not come with insulation.
I have noticed however that some older construction do come with cork wood panelled walls (I dont know if this is for aesthetic reasons) which sure has some sound and thermal insulating properties. Portugal is one of the world producers of cork wood.
If an insulating barrier with stryrofoam is an option, I would prefer it to rockwool/fiberglass becasue of the higher R value (saving me some space) and I feel more confident working with styrofoam - and also because it is cheap, I could do some experimenting. I guess I was just more concerned of the flamambuility issue of styrofoam but with panelling and some extra treatment, I can circumvent it.
Finally, as far as venting goes, would it be OK to vent to the outside instead ?
Cheers, Tuka
11-25-05, 10:27 AM aminator2002 Typically we just have weep holes in the masonry wall to the outside. Weep holes allow trapped moisture to flow to the outside of the wall. Typically a small wicking rope is put into the weep hole to assist in moving the moisture to the exterior. The inside face of the wall is sealed up as well as possible. I've never heard of venting the inside of a wall, but hey... I learn something new everyday.
11-25-05, 02:41 PM bedstor
quote: Originally posted by aminator2002: I've never heard of venting the inside of a wall,
In our neigborhood the landlord installed inside vents to stop damp/mould patches forming Has to have 2. 1 on either side of the room to an outside wall. Only outward appearance is 2 external vents in the brickwork and as a bonus it circulates the air flow in the cavity between the internal/ external brickwork Workman did the job in half an hour Smile So for this Job fitting an external vent/s with an air gap 0f say 6 inches? behind (to aid circulation and any drainage) might be beneficial? (and its cheap!) Smile
11-28-05, 01:55 PM DvdGStwrt Yes for buildings that will have an additional stud frame/drywall interior against the exterior brick wall there is wicking holes/ventilation in brick buildings. If the building was built with the intention of having exposed brick on the interior, then that ventilation is the fact that the brick is open to the interior room. This is my assumption that the brick is not vented already through the roof/crawlspace or somehow to the exterior. I am assuming a cheaply built building with as few of the amenities as possible.
The thickness of the wall is also clue. If it is a house structure it will most likely be either two thicknesses of brick tied together side by side or a single thickness of brick with an interior stuff frame for drywall on the interior side (most likely, I have seen singly thickness of brick for exterior walls on small older structures without internal studwork). If it is factory/multistory building, it could be two thicknesses of brick with rebar and filler material (coarse concrete material) filling the space. The amount of condensation claimed above would suggest to me that there is no hollow space, no internal brick wicking/venting.
My assumption with the vapor barrier is on the wood frame (back) to protect the wood from excess moisture, not on the brick itself which could trap moisture depending on just how much condensation on the brick takes place. Brick (masonry) are thermal masses, thus the thicker the wall the longer the delay for the wall to heat up/cool off thus in spring and fall the differences in temperature would naturally lead to more condensation on the brick, especially the interior where we tend to make the rooms warmer/cooler than the outside. I’m assuming an isolation of the interior stud wall from the exterior brick wall protecting the framing and letting the brick be.
Even sealing off the wall will not remove moisture from the brick itself. Brick is porous - soak a brick in water over night and it will remain clammy and damp for hours after taking it out of the water. Same thing applies in the atmosphere, if there is humidity outside it will work its way into the brick, "seeping" or "wicking" through the brick over time.
I am assuming a wall that is two bricks thick (front to back) without a hollow space in between. Without knowing the age of the building, the kind of masonry laid (how it was laid, the type of brick) I make the assumption that this was an economic build meaning that it was built out of regular brick with the least amount of material. Since there is already an issue of condensation on the interior wall, I assume that that will continue to be an issue even when walled off. There is no "perfect" insulation, heat/cool differences between inside and outside will lead to condensation issues - granted not as much as there is now, but still enough to where it could lead to mold/mildew/rot (of nearby wood).
If the area you live in has high humidity sealing in that brick on the interior will not stop the accumulation of moisture, it will only trap the moisture on the brick will lead to the brick crumbling/rotting itself. The water vapor will “soak” into the brick from the exterior and wick through to the interior. A minimal amount of venting will allow water vapor to escape without presenting a draft issue.
Insulating foam is not very fire resistant itself – even the new foams being used – although retarded from fire, they are supposed to be sheathed with drywall or other flame resistant materials.
My assumptions are:
1. The brick wall is intended to be exposed to the interior thus is not vented/wick holed with the intent of a secondary inner wall material placed on the brick. Further that we are talking about your basic generic building brick with is porous and will accumulate plenty of moisture from the exterior.
2. That attaching any kind of paneling to the brick itself would be near impossible or lead to disintegrating brick or the material itself – i.e. using adhesives on the back of the rock wool on the brick would cause the brick directly beneath the adhesive to start to crumble.
3. That you wanted/needed extra insulation.
4. That you wanted to do this cheaply and as simply as possible without actually reengineering the brick wall.
5. Wanted a method to seal off that wall without having to lose too much interior space to 4-5 inches of studwork and interior cladding.
6. Didn’t want to fuss with Fibreglass.
11-29-05, 07:37 AM Tuka David,
It is cool to see how a potential solution gets refined with time and feedback as our overall understanding increases. really neat. Thanks also for your through feedback.
Your assumptions are pretty much all correct. It seem like I will have to do some venting if i dont want any moisture problems. However someone offered up a solution in another forum that I would like to know your or anybody elses opinion. It is a hybrid of rockwool and styrofoam and seems to eliminate the airgap with the use of a product called Dry-Loc to stop humidity seeping in through the brick. See excerpt below
quote: "If it was mine I would seal the back side of the brick with Dry-Loc Install 2" styrafoam glued to the brick. Seal side gaps and top with spray expanding foam, cover all 2 X 4"s with 6 mil plastic. Now cover the 2 X 4's with 1/2" sheetrock and panel over. Now you have a vaper barrier, a fire brake, insolated wall and a finished wall. If you just nail the paneling to the studs it will never lay flat without the sheet rock backing it and there will be gaps at the top and the baseboards."
I thought it would would be a more complete approach where I can still use styrofoam with rockwool as a fire barrier (brake) since one of my concerns is the fire issue with styrofoam. Any input would be apreciated.
Continuing with your reply I have the following question:
based on your reply what kind of material could i use to move off the paneling slighly from the brick wall so that it is not directly in contact with wood ?
I definitely dont want to leave any insulation in contact with the wall - which is why i want to go the way of an air gap between the insulation and the wall.
Cheers, Tuka
edited to remove code.
This message has been edited. Last edited by: Tuka, 11-29-05 08:38 AM
11-30-05, 01:40 PM DvdGStwrt TThe frame itself I would attach to the floor and ceiling and the wall perpendicular to the brick wall on either side: However a thought occurred to me that you may not have any floor and ceiling studs/joists/beams close to the brick wall to attach the new wall to.
Is that brick wall a load bearing wall? That means that the beams/joists of floor and ceiling would have their ends abutting or resting on that wall. Thus they would be every 16 inches and easy to find with either stud finder or pilot holes. If not, then the joists beams would run parallel to the wall possibly as far as 16 inches from the brick. However I would assume that at the brick wall or the corners where the other two walls meet you will most likely find a stud/post most likely attached to the brick. You could use ‘L’ brackets attached to those posts/studs attached to the new framework.
Conversely there is slotted angle iron which comes with holes:
Which may work easier for you since you are dealing with only one piece of material instead of many individual pieces that have to be aligned and screwed into place.
I would use 1 inch ‘L’ brackets set every 8 to 10 inches attached to the frame you are building – or use one strip of slotted angle iron screwed into the back of the upright stud a screw every 8-10 inches. || L === Where || is the existing wall L is your angle iron === is the upright viewed from the top
Square/level/plumb the frame then attach to the corner post/beams that are existing. Most likely you will have to set your bottom sill plate (the framing member that runs across on the floor) then set your first two upright supports that are attached to the corners with your ‘L’ brackets leaving enough room for a snug fit for your ceiling sill plate (the frame that runs along the ceiling) then cut and fit each upright there after to fit snuggly between both sill plates. Use screws and pilot holes angling in from the sides into the sill plates: \ || / === Where: \ and / represent your screws || represents the upright === represents the sill plate.
I am making another assumption here that since this is an apartment you do not want to do any permanent building/changes to the structure – thus a partition wall that can easily be removed by the landlord leaving minor holes to be filled.
This message has been edited. Last edited by: DorianGreyed,
Posts: 6 | Location: Portugal | Registered: 11-22-05
