Hello.
I have just started building a new boiler room out in the garage and have therefore torn down the old (but unused) boiler room that was already there. When I demolished one of the walls, I discovered moisture and mold that it seems the previous owner tried to address.
Pictures and explanations at: http://wot.se/drupal/node/4 (couldn't link, too few posts)
Now I'm wondering how to prevent it from happening again in the easiest way. It seems a bit like water is seeping up between the two slabs (the garage was built in two stages, this is the new part), and possibly in the lecablocks that form the foundation for the old boiler room walls.
The moisture is present under the floor to some extent, and on top of the lecablocks.
My thought is to remove the floor until I can see how bad it looks, how far it has spread, and then build the wall a little beside the built-up leca part since I need a slightly wider boiler room than the previous size. I plan to build with metal studs and double plasterboard on the boiler room side to make it stable and avoid crooked studs (I have enough of those inside the house), but how do I make sure not to have moisture and mold problems in the future?
Sill seal is a must, but should it be enough to have it stick out beyond the plaster, or could it be an idea to extend the moisture barrier under the wall? The garage is not heated today, but it is partially prepared for that.
Grateful for tips, even if it might not be entirely clear today how it will look and how it looks.
Best regards,
Mattias
I have just started building a new boiler room out in the garage and have therefore torn down the old (but unused) boiler room that was already there. When I demolished one of the walls, I discovered moisture and mold that it seems the previous owner tried to address.
Pictures and explanations at: http://wot.se/drupal/node/4 (couldn't link, too few posts)
Now I'm wondering how to prevent it from happening again in the easiest way. It seems a bit like water is seeping up between the two slabs (the garage was built in two stages, this is the new part), and possibly in the lecablocks that form the foundation for the old boiler room walls.
The moisture is present under the floor to some extent, and on top of the lecablocks.
My thought is to remove the floor until I can see how bad it looks, how far it has spread, and then build the wall a little beside the built-up leca part since I need a slightly wider boiler room than the previous size. I plan to build with metal studs and double plasterboard on the boiler room side to make it stable and avoid crooked studs (I have enough of those inside the house), but how do I make sure not to have moisture and mold problems in the future?
Sill seal is a must, but should it be enough to have it stick out beyond the plaster, or could it be an idea to extend the moisture barrier under the wall? The garage is not heated today, but it is partially prepared for that.
Grateful for tips, even if it might not be entirely clear today how it will look and how it looks.
Best regards,
Mattias
The cause of the moisture is that the capillary-breaking layer outside the Leca concrete is inadequate, and the heat inside causes moisture transport through vapor pressure.
The choice of materials such as gypsum and chipboard is completely insane in that environment with wooden studs and fiberglass insulation.
A moisture barrier causes mold if a space isn't heated because the moisture migrates in the other direction then.
I would completely change the construction...
1. Ventilated floors with Platon, then insulate with floor heating panels, preferably 300mm or alternatively using a Nivell floor system.
2. Replace the wall studs with metal and insulate with cellulose and boron salt, but ensure you maintain a ventilation gap against the outer wall, for instance by using a grooved EPS piece against the Leca.
The choice of materials such as gypsum and chipboard is completely insane in that environment with wooden studs and fiberglass insulation.
A moisture barrier causes mold if a space isn't heated because the moisture migrates in the other direction then.
I would completely change the construction...
1. Ventilated floors with Platon, then insulate with floor heating panels, preferably 300mm or alternatively using a Nivell floor system.
2. Replace the wall studs with metal and insulate with cellulose and boron salt, but ensure you maintain a ventilation gap against the outer wall, for instance by using a grooved EPS piece against the Leca.
More pictures: wot.se/drupal/node/5
Here, you can also see the joint between the old and new slab where I believe moisture is seeping up. It's quite wet on the outside of the wall perpendicular to the joint now during snow melt season.
The Leca is built up on the slab, or maybe into the slab, I'm not really sure, but it goes perpendicular to the edge of the slab.
The space is not heated and, as far as I know, it never has been, at least not since the extension. However, there is an electric heater in the room behind the boiler room. It will get warmer there once the boiler is in place and heating in the space.
1:
I don't really have the space (or budget) to build a 300 mm floor. Now I suspect that the moisture comes from the joint between the slabs. Is there something I can apply to that joint to make it watertight (probably not), or is it possible to warm and ventilate just that space using heat from the boiler and thereby remove some of the moisture? That is, about 10 cm out from the joint under the raised floor.
I assume there won't be any moisture problems even if I do nothing at all about what will be in the boiler room since it will then become a heated space and thus moisture will migrate the other way. What's left is to address what ends up behind the interior wall. Am I wrong in this?
2: Are you thinking here that I should build out from the current wall with insulation and metal studs or replace the existing exterior wall? I had actually planned to cast a slab for the boiler to sit on at the level of the Leca, which means I would only have the wall above the Leca, not beside it. Wouldn't this work?
Here, you can also see the joint between the old and new slab where I believe moisture is seeping up. It's quite wet on the outside of the wall perpendicular to the joint now during snow melt season.
The Leca is built up on the slab, or maybe into the slab, I'm not really sure, but it goes perpendicular to the edge of the slab.
The space is not heated and, as far as I know, it never has been, at least not since the extension. However, there is an electric heater in the room behind the boiler room. It will get warmer there once the boiler is in place and heating in the space.
1:
I don't really have the space (or budget) to build a 300 mm floor. Now I suspect that the moisture comes from the joint between the slabs. Is there something I can apply to that joint to make it watertight (probably not), or is it possible to warm and ventilate just that space using heat from the boiler and thereby remove some of the moisture? That is, about 10 cm out from the joint under the raised floor.
I assume there won't be any moisture problems even if I do nothing at all about what will be in the boiler room since it will then become a heated space and thus moisture will migrate the other way. What's left is to address what ends up behind the interior wall. Am I wrong in this?
2: Are you thinking here that I should build out from the current wall with insulation and metal studs or replace the existing exterior wall? I had actually planned to cast a slab for the boiler to sit on at the level of the Leca, which means I would only have the wall above the Leca, not beside it. Wouldn't this work?
I think I've figured out where the moisture is coming from...
The beam is against the outer wall of the old section, and the mold originates from the joint between the plates.
I haven't found any other place where the moisture is coming from, including under the lecan, so it's probably coming from here.
So I wonder:
Is there something I can smear in the joint to seal it?
Is it okay to lay more concrete against that joint and hope it turns out well?
Is it enough if I ventilate the nearest section with heated boiler room air?
I'll probably have more questions later, but it feels a bit better now that it doesn't seem to be coming from the lecan.
The beam is against the outer wall of the old section, and the mold originates from the joint between the plates.
I haven't found any other place where the moisture is coming from, including under the lecan, so it's probably coming from here.
So I wonder:
Is there something I can smear in the joint to seal it?
Is it okay to lay more concrete against that joint and hope it turns out well?
Is it enough if I ventilate the nearest section with heated boiler room air?
I'll probably have more questions later, but it feels a bit better now that it doesn't seem to be coming from the lecan.