UFH Condensation Advice

[Psykotik]

Hi all,

I'm looking for some advice please?

I'm currently building a 2 storey house, and the plastering was finished approximately 4 weeks ago. However, due to the cold weather (it's barely gone above 0°c in the daytime and as low as -12°c during the night, for the past 2-3 weeks) it still hasn't completely dried and there's considerable damp patches in places, which I'd been using a fan heater and dehumidifier that I rented to help the drying process.

The water underfloor heating system was installed in every room, including the garage, under concrete screed (which was laid in December 2024). The UFH was commissioned yesterday (22nd Feb) and I went to check how it was looking today. The heating is currently at 15.5°c and is expected to rise gradually with the commissioning cycle.

Now, although I expected some condensation, I was shocked at the sheer amount! Most of the walls are showing signs of heavy condensation. However, the garage seems to be the worst because every inch of the walls and ceilings are covered with surface moisture.

So, I did what anyone would do... I asked my Dad. He simply suggested giving it a week to see how it goes.

My question is, should I be concerned? Is there anything I can do to remove the moisture, or is this just a normal part of the process? Should I hire some dehumidifiers again?

Any advice would be greatly appreciated

* PHOTOS TO FOLLOW *

~ Psykotik

 

[Murdochcat]

Open windows. Drying new plaster means a LOT of moisture

Much better than relying on dehumidifier’s

 

[Psykotik]

Open windows. Drying new plaster means a LOT of moisture

Much better than relying on dehumidifier’s

Yes, I was considering doing that, but I'm hesitant to, as the heat pump / UFH installer said it's not necessary. He also said the commissioning process takes 28 days.

For a bit more context, the house is 260m2 and located in Poland, so we're planning to insulate the exterior walls, and apply spray foam to the interior of the pitched roof. However, currently there's zero insulation, therefore opening windows would only drive the heating bill even higher - especially given the 28 day comissioning period - hence my hesitancy.

 

[Ivor Windybottom]

My unqualified suggestion would be to open all the windows a small amount, just enough to let the air change but while still allowing the temperature to rise.

Dehumidifiers cost money to run too.

 

[Murdochcat]

Yes, I was considering doing that, but I'm hesitant to, as the heat pump / UFH installer said it's not necessary. He also said the commissioning process takes 28 days.

For a bit more context, the house is 260m2 and located in Poland, so we're planning to insulate the exterior walls, and apply spray foam to the interior of the pitched roof. However, currently there's zero insulation, therefore opening windows would only drive the heating bill even higher - especially given the 28 day comissioning period - hence my hesitancy.

Moisture coming out of the drying walls and floors has to go somewhere - out of an open window would be extremely efficient

 

[noseall]

Hi all,

I'm looking for some advice please?

I'm currently building a 2 storey house, and the plastering was finished approximately 4 weeks ago. However, due to the cold weather (it's barely gone above 0°c in the daytime and as low as -12°c during the night, for the past 2-3 weeks) it still hasn't completely dried and there's considerable damp patches in places, which I'd been using a fan heater and dehumidifier that I rented to help the drying process.

The water underfloor heating system was installed in every room, including the garage, under concrete screed (which was laid in December 2024). The UFH was commissioned yesterday (22nd Feb) and I went to check how it was looking today. The heating is currently at 15.5°c and is expected to rise gradually with the commissioning cycle.

Now, although I expected some condensation, I was shocked at the sheer amount! Most of the walls are showing signs of heavy condensation. However, the garage seems to be the worst because every inch of the walls and ceilings are covered with surface moisture.

So, I did what anyone would do... I asked my Dad. He simply suggested giving it a week to see how it goes.

My question is, should I be concerned? Is there anything I can do to remove the moisture, or is this just a normal part of the process? Should I hire some dehumidifiers again?

Any advice would be greatly appreciated

* PHOTOS TO FOLLOW *

~ Psykotik

Are the walls insulated?