Hello,
we are planning to insulate our roof and, in this process, have it re-covered and extended.
I have now received a quote for the roof, and I find the costs for the insulation absolutely incomprehensible.
They are charging €70 per m² (net) for insulating 140 m² (1507 sq ft) with ISOVER 180mm (7 inches) 035.
This price is exclusively for the insulation itself. All other work, including the vapor barrier, is listed separately.
For me, as a private customer, ISOVER 180mm 035 costs about €7 per m² (net).
If I calculate what I consider a fair estimate of 15 minutes per m² for installation, at an hourly wage of €50, which is also stated in the quote, I come to €19.50 per m².
Am I completely wrong here? I shouldn’t need to allow more than one hour of installation time per square meter for cavity insulation between rafters, should I?
It is clear that I will get more quotes, but I would like to hear some rough benchmarks on how long such cavity insulation typically takes. Or how long it takes to install a vapor barrier for around 120–140 m² (1292–1507 sq ft).
Thank you for your advice.
we are planning to insulate our roof and, in this process, have it re-covered and extended.
I have now received a quote for the roof, and I find the costs for the insulation absolutely incomprehensible.
They are charging €70 per m² (net) for insulating 140 m² (1507 sq ft) with ISOVER 180mm (7 inches) 035.
This price is exclusively for the insulation itself. All other work, including the vapor barrier, is listed separately.
For me, as a private customer, ISOVER 180mm 035 costs about €7 per m² (net).
If I calculate what I consider a fair estimate of 15 minutes per m² for installation, at an hourly wage of €50, which is also stated in the quote, I come to €19.50 per m².
Am I completely wrong here? I shouldn’t need to allow more than one hour of installation time per square meter for cavity insulation between rafters, should I?
It is clear that I will get more quotes, but I would like to hear some rough benchmarks on how long such cavity insulation typically takes. Or how long it takes to install a vapor barrier for around 120–140 m² (1292–1507 sq ft).
Thank you for your advice.
That seems quite expensive to me. Especially since installing insulation batts in new construction (okay, you’re renovating… so uneven rafters?) is something even a trained orangutan could manage. That’s why we did it ourselves. We had “only” about 100 square meters (1,076 square feet) to cover, and with 220mm (8.7 inches) mineral wool for insulation alone, it took three people two days. Two of us could have done it in two days as well. Installing, sealing, and stapling the vapor retarder then took another two and a half days. That was a bit tricky for us, apart from the skylight, but overall fairly straightforward. I did the sealing alone, and honestly: I’m glad I did it myself because I doubt any professional would have done it more carefully. The blower door test is still pending, but I’m optimistic.
The counter-battening took about four relaxed days, though it could be done faster. We have knee walls almost 2 meters (6.6 feet) high, an open roof structure, and a gallery, which meant ladders were needed almost everywhere.
Get more quotes and reconsider whether you really want fiberglass insulation. Mineral wool has a slightly higher density, providing better protection against summer heat. Even better would be wood fiber insulation, but unfortunately that comes with a higher price. On the plus side, it smells nice like popcorn and doesn’t cause itching.
So, to summarize: if you have a few days, do it yourself; if not, get more quotes. I can’t remember exactly what was offered to us, but despite the greater insulation thickness and including the vapor retarder, it was clearly cheaper—though that was for new construction.
The counter-battening took about four relaxed days, though it could be done faster. We have knee walls almost 2 meters (6.6 feet) high, an open roof structure, and a gallery, which meant ladders were needed almost everywhere.
Get more quotes and reconsider whether you really want fiberglass insulation. Mineral wool has a slightly higher density, providing better protection against summer heat. Even better would be wood fiber insulation, but unfortunately that comes with a higher price. On the plus side, it smells nice like popcorn and doesn’t cause itching.
So, to summarize: if you have a few days, do it yourself; if not, get more quotes. I can’t remember exactly what was offered to us, but despite the greater insulation thickness and including the vapor retarder, it was clearly cheaper—though that was for new construction.
Zaus09 schrieb:
.... Yellow glass wool insulation is rarely suitable for pitched roofs! At best, it can be used for flat roofs or between ceiling joists. QUOTE="Zaus09, post: 63808, member: 21761"]...Or how long it takes to install a vapor barrier for 120-140m² (1,292-1,507 sq ft)....[/Quote] The exact durations are calculated by the respective contractor!
Best regards.
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