Installing loft insulation

Electricity - French regulations & supplies; Insulation, Brickwork, Roofs, Joinery, Flooring, etc
User avatar
Posts: 82
Joined: Tue Sep 21, 2021 8:41 pm
Location: Vendée

Installing loft insulation

#11 Post by Biloute »

Hi Veem!
Even though I lived closer, I can no longer work for anyone else. My 74-year-old body no longer allows me to work in difficult positions without being tortured. 😥 I continue to renovate our house but taking frequent breaks: I move forward like a snail! But I am ready to advise friends and let them benefit from my 50 years of building experience, including 20 as a craftsman practicing all trades.
Just out of curiosity, I just googled "cut glass wool": everyone suggests cutting with serrated knives or saws. What an horror for the quality of the cut and the dust generated! The cut is jagged as if torn instead of cut. With my "aluminum ruler + stanley knife" method, the cut is as clean and square as the other edges of the material and there is very little dust. And what a time saver! 😀
This is essential to avoid thermal bridges: with a clean cut there are no small spaces where air can pass. There is no point in putting in very thick insulation if it is installed incorrectly... A thermal bridge is like a tiny hole in the bottom of a saucepan: even if the bottom is very thick, the water will flow!😪
It's good to wear masks and goggles, but if you work for hours, the dust ends up getting on the sides. Keeping the windows open helps a bit. Vacuuming often is also a good idea because, when walking, you raise dust in the air (forget the broom, except by spreading wet sawdust before).
The manufacturers have greatly improved the insulations over the years: they can be handled without scratching too much because the glass wool is now encapsulated. On the other hand, the problem of dust remains when cutting.
Don't hesitate to ask me for more details!
Good luck anyway !
Demain est le premier des jours qu'il nous reste à vivre: profitons-en ! :D

Posts: 557
Joined: Mon Aug 23, 2021 1:47 pm
Location: Saumur

Installing loft insulation

#12 Post by hughnique »

Some time back a lot of these DIY renovation programmes had the digger in the garden excavating trenches for pvc pipes to be installed and then buried, I understood the pipes were filled with water and the natural heat of the earth warmed the water in the pipe. Something I always found hard to swallow TBH, so why am I putting down a wooden floor, chevrons and OSB sheets, and filling in between the floor joists with glass fibre insulation, I am told it stops the heat from disappearing into the ground, which somehow contradicts, the statement I made earlier.

Posts: 1249
Joined: Mon Jul 12, 2021 9:57 pm
Location: Auvergne Rhone Alpes

Installing loft insulation

#13 Post by exile »

No @hughnique . It is part of the same principle.

The Earth absorbs heat - it could be from your poorly insulated floor but mostly it is from the sun - either directly when it shines or from the warmed air above it when the sun is not shining.

The ground acts like a massive storage heater. At the surface it will give off its heat, so on a cold day it may be covered in frost. Frost that might stay all day on a cold day. But go down around 1m and the temperature of the ground stays just about constant all year round. This is something I discovered with my caving and potholing. Once inside the cave the air temperature remains very constant (breezes notwithstanding) and it is the same in winter as in summer. Yorkshire caves around 7-8C; Mendip 9C; Vercors France (10-11C) and so on.

So go down in the ground with your pipes and they will warm up/cool down to a near constant temperature all year round. You can extract that heat by circulating water and using a heat exchanger to pull out some of the energy in the water and pushing it into your home. Meanwhile the cooled water circulates back under the ground to be re-heated.

Posts: 481
Joined: Tue Jul 13, 2021 7:59 am
Location: 16

Installing loft insulation

#14 Post by Spectrum »

You need to go down a deep mine shaft to feel how warm it is under ground. The type of heating you are looking at is called
" A Ground source Heat pump".

User avatar
Posts: 238
Joined: Tue Jul 27, 2021 4:41 pm
Location: 52 & 71

Installing loft insulation

#15 Post by Loup-garou »

Veem wrote: Sat Nov 19, 2022 7:55 pm It was actually Biggles who posted the OP under my name but he has now joined the forum and will, I hope, get back to you. Disposable overalls and proper masks have now arrived, so just goggles to come and then he'll be wanting to make a start.
Biggles has no goggles!!!! He's a fake, ........................ the real Biggles never went anywhere without his goggles. :oops:

Posts: 1249
Joined: Mon Jul 12, 2021 9:57 pm
Location: Auvergne Rhone Alpes

Installing loft insulation

#16 Post by exile »

Spectrum wrote: Mon Nov 21, 2022 8:12 am You need to go down a deep mine shaft to feel how warm it is under ground. The type of heating you are looking at is called
" A Ground source Heat pump".
Totally agree but all of the ground based systems tend to be called geothermal, when as I suggested above the shallow systems are actually solar based. As you suggest proper geothermal really relies on deep sourced heat.

I have had the opportunity to go down Boulby Potash mine with a winding shaft that is over 1100m and there you certainly do feel the heat - 104F. That however means you need a deep borehole to be able to access that heat.

Posts: 3
Joined: Tue Oct 11, 2022 11:52 am

Installing loft insulation

#17 Post by Biggles »

Loup-garou wrote: Mon Nov 21, 2022 9:56 am Biggles has no goggles!!!! He's a fake, ........................ the real Biggles never went anywhere without his goggles.
The Mk 8 Flying Goggles are far too expensive (and ineffective) to use for this job but they are brilliant in an open cockpit! :D
Suitable goggles arrived today, so that is the PPE complete - tomorrow I shall make a start. My thanks to everyone who has contributed their knowledge and experience to this thread. :geek:

Posts: 1369
Joined: Thu Jul 15, 2021 7:00 pm
Location: Near Confolens in Charente

Installing loft insulation

#18 Post by Veem »

I was uneasy about Biggles working up in the lofts so found a FB group for local tradesmen. We contacted someone very local to us who came to give a quote on Thursday, came again with a mate to break the back of the job on Friday and finished off with a couple of hours yesterday. Both men were far younger and more nimble than Biggles is now and were well worth paying. Job done. Thanks for your input though and I'm grateful to say that in the end, we didn't need it! :clap: :clap: :clap:

User avatar
Posts: 1242
Joined: Mon Jul 12, 2021 8:31 pm
Location: Brittany 22

Installing loft insulation

#19 Post by Hotrodder »

Good to hear you got it sorted, and without risk.

I have been putting off cutting back a line of laurel hedging that has grown too high and menacing a telephone wire at the edge of our property. I figure I will get a dry spell some time this winter and get stuck in with my trusty chainsaw. I'll just butcher it down to about two metres. There was a knock on the door the other day and a French chap asked if I needed any tree or hedge work doing. On a whim I relented to show him the laurel and asked what he might charge. Access is not very challenging and the row is only about 8 or 9 metres in length. He quoted €700. :o When my heart started beating again he said if I would be prepared to deal with the cuttings he would do it for €600. I tried to be as pleasant as I could as I showed him back to his van with a polite refusal.
Now I know how the French can afford the new cars and the expensive artisan foods and good wine. They are making a mint from the rich Anglais. :?
"Life: terms and conditions apply. Offer ends soon."

User avatar
Posts: 774
Joined: Sat Jul 17, 2021 3:10 pm
Location: Nièvre

Installing loft insulation

#20 Post by RobertArthur »

@ Hotrodder, I should be a rich man by now. In 2003 about 750 euros bought me a long and powerful taille haie, made by STIHL. Two times a year about 150 meters of hedges. Although it takes me today many more hours to finish the job than in the past.....Chainsaw work the same, so I can't blame STIHL.

Post Reply