extra insulation on self build

jr,interested in your polish windows- am getting quotes at the moment and would like to price abroad,have you a web address for them?and have they low u-values as i am going with underfloor heating

micheller said:

Sorry to jump on the OP's question, would anyone care to help/comment on the following:

we are not going to dry line, instead opting for hard plaster with double the recommended insulation depth between blocks using Sheepswool insulation.
The house will also have underfloor heating (with consequent long start up/slow down times).
Based on what has been said above about dry lining having quick heat up & down times, I'm reading that what we are doing is a good idea for heat retention and underfloor heating? Am I right on that one?

Hope that reads okay, I'm not very technically knowledgeable in this area!

Thanks in advance for any help

Click to expand...

Hi Michelle

I must stress I'm no expert on this but when using underfloor heating the method you are proposing seems to be what is regarded as best practice....that is you heat the thermal mass and have a constant more even heat for longer periods.

that said heating thing is a horses for courses game and optomistic made a valid point when pointing out heat up times!! they are much longer and it is best for a family home that is occupied for much of the day.

one way to overcome this is by installing an intelligent controller that will regulate itself to have the temp at a set level at certain times during the day. It will then come on at perhaps three to be warm for five and shut off earlier as well. the more input it gets like
1)return water temp in the ufh
2)temp of the room/zone
3)temp of outside conditions
4)temp of available heat sources
the better it will be able to regulate itself.


best of luck with the build

Cheers, that's useful to get some validation

Hi Fisherman I got the windows off a guy who brought over his own for his self build and brought over a few other lots for other people the specs for these are as follows (I am very happy with the Windows)Off-the-shelf PVC windows and doors are equipped with glazing units with low-emissivity glazing and argon gas fill, a heat-transfer coefficient U ≤ 1.1 W/m2K and acoustic resistance Rw ≤ 31 dB.

I have used the sheepswool insulation (100mm) in my new build. This means that the insulation is in contact with both the outer and inner leafs. After the recent storms some of the internal walls are wet. I am now concerned that there is moisture cross over from the outer leaf to the inner leaf. The house is not plastered yet, but I think if I was doing it again I would use a high density board thinner than the cavity.

Froggie,
I would think that you have a huge problem with your cavity if what you say is right. Is there any ties keeping the insulation in place? Is your insulation the exact size of the cavity? Who specced this detail

My builder suggested this type of insulation, my Architect was not in favour. The blame must lie with me as I had the choice...