ᐅ Pressure testing underfloor heating before screed installation – risks?
Created on: 31 May 2014 13:04
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ElinaWe want to install underfloor heating in our old building. Since a wet screed is not an option (due to weight and wooden walls), it has to be a dry system. Unfortunately, even after extensive searching, we have not found a company willing to do this because they always require minimum areas (usually 100 sqm (1,076 sq ft)). This is not possible for us, as the old building is occupied and we cannot clear 100 sqm (1,076 sq ft) at once. It can only be done room by room.
So now we have to do it ourselves. The problem is that we cannot find a professional to perform the pressure test, and we were also told that a water pressure test can only be done if commissioning follows shortly after. That would not be possible for us since we have to fit out all the rooms one by one, which will probably take a very long time—certainly at least six months to a year.
Leaving the underfloor heating pipes exposed for that long is also not possible because we cannot clear the next room until the previous one has a proper floor again.
Accordingly, our plan is to lay the underfloor heating, then install the dry screed on top, and then move on to the next room. This means the screed would already be in place before the final pressure test occurs when everything is actually finished.
The underfloor heating manufacturer says that if we use aluminum composite pipe (the most expensive option), this should not be a problem. The pipes themselves are apparently always (?) leak-proof. The weak points are the connections at the manifold, but these would still be easily accessible later.
There are no interruptions in the pipes within the heating circuits, so our planned approach should be acceptable and the risk that a brand-new aluminum composite pipe could have a leak somewhere in between is low.
Before proceeding, I wanted to ask if this is correct or if every room’s piping must be pressure tested individually before the screed goes on (which I don’t know how we would manage, as we are already struggling to find someone who would pressure test a DIY-installed underfloor heating system at all—let alone on a room-by-room basis).
So, what do you think? Can we reasonably do it this way without too much risk, or is the risk too high?
So now we have to do it ourselves. The problem is that we cannot find a professional to perform the pressure test, and we were also told that a water pressure test can only be done if commissioning follows shortly after. That would not be possible for us since we have to fit out all the rooms one by one, which will probably take a very long time—certainly at least six months to a year.
Leaving the underfloor heating pipes exposed for that long is also not possible because we cannot clear the next room until the previous one has a proper floor again.
Accordingly, our plan is to lay the underfloor heating, then install the dry screed on top, and then move on to the next room. This means the screed would already be in place before the final pressure test occurs when everything is actually finished.
The underfloor heating manufacturer says that if we use aluminum composite pipe (the most expensive option), this should not be a problem. The pipes themselves are apparently always (?) leak-proof. The weak points are the connections at the manifold, but these would still be easily accessible later.
There are no interruptions in the pipes within the heating circuits, so our planned approach should be acceptable and the risk that a brand-new aluminum composite pipe could have a leak somewhere in between is low.
Before proceeding, I wanted to ask if this is correct or if every room’s piping must be pressure tested individually before the screed goes on (which I don’t know how we would manage, as we are already struggling to find someone who would pressure test a DIY-installed underfloor heating system at all—let alone on a room-by-room basis).
So, what do you think? Can we reasonably do it this way without too much risk, or is the risk too high?
Elina schrieb:
.....Because a wet screed is not suitable (weight, wooden walls), it should be a dry system.... Whether you absolutely must use a drywall system is a personal decision. They are less energy efficient and more expensive when calculated per square meter. This is especially true for older buildings, where the heating load can be significantly higher than in new constructions.Elina schrieb:
.....So what do you think, can this be done relatively safely like this ... Yes. If you have installed the underfloor heating yourself, although I am not sure if it is properly sized, you can also perform the pressure testing yourself.Best regards
The alternative to the dry system would be no underfloor heating at all. As mentioned, wet systems are not an option, and the installation height is also an issue. It’s an old building with the typical problems you often encounter. Additionally, we wouldn’t be able to let the screed dry for weeks, plus all the moisture… there are already furniture pieces inside. Lastly, a wet screed is ruled out because the site is inaccessible to vehicles, and the screed would have to be pumped 30 meters (98 feet) horizontally and 10 meters (33 feet) vertically; that wasn’t possible even with pellets, so I assume it would be similarly difficult with screed.
We also don’t want radiators; there were none before, so no pipes or recesses, and I find the look outdated.
The only remaining option would be wall heating since we are reboarding all the walls anyway. We will have to do this in the bathroom too, as additional installation height isn’t possible. The only concern I still have is that I’d like to have warm feet.
Is wall heating, which is also installed as a dry system (sometimes looking exactly the same in product images), more efficient than underfloor heating?
We also don’t want radiators; there were none before, so no pipes or recesses, and I find the look outdated.
The only remaining option would be wall heating since we are reboarding all the walls anyway. We will have to do this in the bathroom too, as additional installation height isn’t possible. The only concern I still have is that I’d like to have warm feet.
Is wall heating, which is also installed as a dry system (sometimes looking exactly the same in product images), more efficient than underfloor heating?
Elina schrieb:
.....We don’t want radiators either; there weren’t any before, so no pipes or niches, and I find the look outdated.... Radiator niches are a concept from the last century and are generally no longer used today. Of course, radiators need to be connected, which can also be done via underfloor heating.Elina schrieb:
....
The only option left might be wall heating, since we are replanking all the walls anyway.... Wall heating on interior walls could be an alternative. However, the walls must be able to radiate freely. On exterior walls, it is significantly more challenging, especially with a high U-value of the exterior wall and high flow temperatures. The additional insulation required increases costs and reduces living space.Elina schrieb:
....is wall heating, which is also installed as a dry system (and looks exactly the same on some product images), more efficient than underfloor heating? No. Wet systems are generally much more efficient. Basically, for the proper design of heating surfaces, the room heating loads must be known first—regardless of whether it is radiators, underfloor heating, or wall heating. The permitted flow temperatures are limited (maximum heat flux density, e.g., in living areas). Simply embedding some pipes anywhere at random is likely to cause serious problems.Best regards.[/QUOTE]
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