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Am I insulating bungalow loft correctly?

Postby Oppala » Fri Dec 09, 2022 5:53 pm

We recently moved into this 1950s chalet-bungalow. It appeared to me that the existing loft insulation was added in a hap-hazard way, sheet fibre-glass draped over the joists with loose wool fibre scattered over the sheet to add some depth. The rooms below have been very cold so I resolved to improve the insulation.

I have been taking up the existing and separating the two materials, then relaying between the joists (about 100mm depth) to pack more evenly to upper joist level. I plan to add a new layer of loft roll over the top of the existing, perpendicular to the joists to add a further 100mm depth.

However I have found that whomever laid the original sheet insulation had used thin battens across the joists, presumably to hold the sheet insulation off the ceiling board in places to allow ventilation.

My question, am I OK to pack the existing insulation between the joists, knowing that I will be adding another layer? Do I need to allow for ventilation? If yes, how?

I haven't packed anything in the rafters and have allowed gaps at the roof edges. I have already added 75mm insulation board between the rafters where the roof slopes over the house but again have allowed gaps for air circulation.

I have added a photo of my efforts so far.

Apologies for the long-winded question.
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Simply Build It

Postby stoneyboy » Sat Dec 10, 2022 11:46 pm

Hi opalla,
Remove the battens and fit insulation between the joists and as far as the wall plates, then add at least a further 150mm over the whole lot.
Your loft space should be cross ventilated - if the soffits are a tight fit you could add soffit vents. It may be easier to fit tile vents.
Regards S
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Postby Oppala » Sun Dec 11, 2022 8:06 pm

Very helpful, thank you. Will do
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