ᐅ Heating screed with a heating device versus a heat pump – costs?
Created on: 14 Sep 2022 22:04
S
Sandra.M85
Hello,
Two weeks ago, the screed (cement screed) was poured in our new single-family home (about 130 sqm (1400 sq ft) floor area).
Our general contractor (GC) now offers us the following options:
1) Heating the screed using a 19 kW heating device, starting in 10 days.
2) Heating the screed via underfloor heating powered by a heat pump after the heat pump is installed in mid-October.
According to our contract, I am responsible for paying the heating costs, while the GC covers construction electricity. The house completion date is set for February 2023 in the contract.
Option 1: The GC says I must pay for the construction electricity used by the heating device because it counts as heating costs. Until now, I assumed that heating costs cover the energy needed to keep the workers working, but not the energy used specifically to heat the screed. If I prefer option 1, I understand that I will have to cover these costs, but the GC will still complete the house by February using the cheaper option 2.
How expensive would option 1 be? What is the cost of construction electricity, and how much electricity is needed to operate the heating device until the screed is dry?
According to the GC, option 1 would allow me to move in this year, which could save me about one month’s rent for my current apartment—around 650 euros—and avoid the risk that the heat pump might not be installed by mid-October, as required for option 2.
Option 2: After the heat pump is installed in mid-October, if the screed is heated via underfloor heating, does the GC cover the electricity used for this? Would this electricity still be measured by the construction electricity meter (paid by the GC according to the contract), or would it already be charged through my new private electricity meter?
How much electricity would be needed to heat the screed this way, and if I had to pay for this electricity, approximately how much cheaper would option 2 be compared to option 1?
Which option would you choose?
Two weeks ago, the screed (cement screed) was poured in our new single-family home (about 130 sqm (1400 sq ft) floor area).
Our general contractor (GC) now offers us the following options:
1) Heating the screed using a 19 kW heating device, starting in 10 days.
2) Heating the screed via underfloor heating powered by a heat pump after the heat pump is installed in mid-October.
According to our contract, I am responsible for paying the heating costs, while the GC covers construction electricity. The house completion date is set for February 2023 in the contract.
Option 1: The GC says I must pay for the construction electricity used by the heating device because it counts as heating costs. Until now, I assumed that heating costs cover the energy needed to keep the workers working, but not the energy used specifically to heat the screed. If I prefer option 1, I understand that I will have to cover these costs, but the GC will still complete the house by February using the cheaper option 2.
How expensive would option 1 be? What is the cost of construction electricity, and how much electricity is needed to operate the heating device until the screed is dry?
According to the GC, option 1 would allow me to move in this year, which could save me about one month’s rent for my current apartment—around 650 euros—and avoid the risk that the heat pump might not be installed by mid-October, as required for option 2.
Option 2: After the heat pump is installed in mid-October, if the screed is heated via underfloor heating, does the GC cover the electricity used for this? Would this electricity still be measured by the construction electricity meter (paid by the GC according to the contract), or would it already be charged through my new private electricity meter?
How much electricity would be needed to heat the screed this way, and if I had to pay for this electricity, approximately how much cheaper would option 2 be compared to option 1?
Which option would you choose?
KlaRa schrieb:
The term "21 days" in DIN EN 1264-4, section 4.2.4, refers exclusively to the waiting time required after the installation of cement screed before it should be heated.Our cement screed was completed last week. My construction company now wants to start the heating phase with the underfloor heating/air-to-water heat pump after about 10 days. Isn’t that 11 days too early? They said this is standard practice and there have never been any problems. Should I insist on waiting and postpone all other trades?
"My construction company now wants to start the heating-up phase with the underfloor heating/air-to-water heat pump next week (after about 10 days). Isn’t this 11 days too early?"
That depends on what the manufacturer of the binder says.
There are cement-based screeds that can be subjected to functional heating earlier than after a waiting period of 14 days.
If heated up too early, the cement stone does not yet have the necessary strength – and it then tends to develop noticeable cracks.
A few cracks may not be a major issue, but if the screed loses the mixing water required for curing too early, it cannot reach its final strength.
So it’s better to ask and get confirmation from the manufacturer.
Regards, KlaRa
That depends on what the manufacturer of the binder says.
There are cement-based screeds that can be subjected to functional heating earlier than after a waiting period of 14 days.
If heated up too early, the cement stone does not yet have the necessary strength – and it then tends to develop noticeable cracks.
A few cracks may not be a major issue, but if the screed loses the mixing water required for curing too early, it cannot reach its final strength.
So it’s better to ask and get confirmation from the manufacturer.
Regards, KlaRa
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