Loft hatch, boarding and insulation questions

Spir4L

singhini said:
No, but I was planning something similar i.e. creating extra storage space and improving the warmth in the house. I kept going around in circles with what installers said and what the internet said, not knowing whether I should or shouldn’t go ahead -----> and in the end i didn’t bother.

I really need the extra space for storage so it's not an option for me 

stuart45

It's not normally a good idea to insulate at joist and rafters level. If you insulate at joist level you need plenty of ventilation which makes a cold roof space. It's pointless insulating at rafter level as well, because any heat will be lost.

Spir4L

stuart45 said:

It's pointless insulating at rafter level as well, because any heat will be lost.

Thanks for your help! Can you please elaborate more on why the heat would be lost? I am not understanding.

stuart45

Spir4L said:

stuart45 said:

It's pointless insulating at rafter level as well, because any heat will be lost.

Thanks for your help! Can you please elaborate more on why the heat would be lost? I am not understanding.

Because cold air is constantly coming in with the required ventilation. The insulation in the joists stops most of the heat getting into the roof space anyway. It's cold, damp air that gets through. That's why you need ventilation.

Spir4L

stuart45 said:

Because cold air is constantly coming in with the required ventilation. The insulation in the joists stops most of the heat getting into the roof space anyway. It's cold, damp air that gets through. That's why you need ventilation.

Thanks, so in conclusion there's no way to make the loft space a bit warmer in the winter and cool in the summer to avoid damaging what I store there? But also to use it as a hobby room (for diy for example)?

stuart45

Spir4L said:

stuart45 said:

Because cold air is constantly coming in with the required ventilation. The insulation in the joists stops most of the heat getting into the roof space anyway. It's cold, damp air that gets through. That's why you need ventilation.

Thanks, so in conclusion there's no way to make the loft space a bit warmer in the winter and cool in the summer to avoid damaging what I store there? But also to use it as a hobby room (for diy for example)?

It can be done, but put the insulation at rafters level. Look up how loft conversions are insulated.

Spir4L

This is an example of a Celotex Wrap work that shows in CheckaTrade, from the picture I would say the insulation is at the rafters level, probably with a certain amount of gap

stuart45

That's insulation at rafter level. 

Smartun

I used the Loft leg system coupled with 18mm osb boards for my Loft.

Loft legs are amazingly strong even though they are injection moulded plastic. The key is to use plenty of them. I have a very big Loft so I used over 200 Loft legs in total. Four 2inch screws per leg each leg screwed onto the joist and then few screws  through the board into the Loft leg heads.

 You are supposed to use 18mm tongue and groove chipboard but I don't rate it. Cut a standard 8 x 4 ft sheet of osb into 4off 2 x 4 boards and they slide right through a standard Loft hatch. If you go to somewhere like b&q they will probably chop a full sheet down for you.

My Loft already had plenty of rock wool insulation so I just boarded over. It's important to let the Loft space breath so I left the trusses and underside of the roof tiles as they were. It is a bit chilly up there but it's only storage space and it won't freeze.

If you use 5 or 6 Loft legs per board section it's easily strong enough.... the roof would collapse before you over loaded the legs. You can buy 175mm Loft legs straight from the UK manufacturer via eBay.

If you want to use the space more permanently you would probably have to skin under the trusses with ply making a box shape inside the Loft. This isn't very hard to do but depending on the shape of your loft you might not have much room. I can stand up in my loft but quickly lose headroom either side of the main center section.

Amazon do a pair if 4ft led light battens for £20... these were enough to light the whole Loft.

Swipe

I'd forget the rafter insulation and throw a tarp over what you are storing if condensation damage is a concern.