1930s Semi Refurb - Part 4 of ... (Edition: Loft Insulation)

[Freefaller]

Yeah that's the stuff. Although I think I've got the 200mm stuff in the basket at the moment. I'm trying to work out the best value by m2 but it's like a GCSE maths problem as they're all different thicknesses and lengths lol.

I already had 170-200mm so only needed it to top up and/or plug the gaps that was needed. If you have nothing then 200mm is bare minimum.

Just plug the values in excel and work out £ /sqm for each roll, and then multiply it by the number of sqm.

 

[dlockers]

I already had 170-200mm so only needed it to top up and/or plug the gaps that was needed. If you have nothing then 200mm is bare minimum.

Just plug the values in excel and work out £ /sqm for each roll, and then multiply it by the number of sqm.

Yeah I was planning on 200m + 100m, but couldn't work out if 3x 100m was cheaper initially (will do the Excel as you said).

Do you need to sink the insulation into the gap between the ceiling joists? Or can it sit "as it falls?"

 

[Mason-]

Yeah I was planning on 200m + 100m, but couldn't work out if 3x 100m was cheaper initially (will do the Excel as you said).

Do you need to sink the insulation into the gap between the ceiling joists? Or can it sit "as it falls?"

I would push some into the gap between the joists, 100mm is probably good. Then run a 200mm on top of that going perpendicularly to your joists. Are you definitely going to use timber instead of loft legs? Seems like it would be a lot more work using timber. And does it really need to be super level?

 

[dlockers]

I would push some into the gap between the joists, 100mm is probably good. Then run a 200mm on top of that going perpendicularly to your joists. Are you definitely going to use timber instead of loft legs? Seems like it would be a lot more work using timber. And does it really need to be super level?

That's a good shout.

I'm still not sure about loft legs...but I'm equally unsure without buying a forest's worth of timber how to baton it out sensibly. Or use noggins and have something even more unstable lol.

Edit: They also say no more than 25kg per square meter which is just LOL?

 

[Mercenary Keyboard Warrior]

That's a good shout.

I'm still not sure about loft legs...but I'm equally unsure without buying a forest's worth of timber how to baton it out sensibly. Or use noggins and have something even more unstable lol.

Edit: They also say no more than 25kg per square meter which is just LOL?

I used this, far better than loft legs IMO since it creates a decent platform thats linked. Its quite quick once you get the first couple in place to act as a working platform

Raised Loft Boarding For Your Home | LoftZone UK

Our BBA-Approved raised loft boarding system saves money, helps the environment and increases safety, without invalidating new build warranties.

www.loftzone.co.uk

 

[Mason-]

That's a good shout.

I'm still not sure about loft legs...but I'm equally unsure without buying a forest's worth of timber how to baton it out sensibly. Or use noggins and have something even more unstable lol.

Edit: They also say no more than 25kg per square meter which is just LOL?

If I read the spec correctly they’re covering their arse. The legs can support more, but the joists are probably more likely to fail before the legs if you overload them. So to save themselves from litigation “you said your legs could take 500kg but when I tried to store my car in my loft the roof caved in!!! Give me money!!!”.

• Loftlegs are strong and can support weights of 500kg however, they do not change the load bearing characteristics of a loft. Structural engineers recommend never storing more than 25kg per square metre of boarded area. Loading limit of existing ceiling structure should be confirmed by a structural engineer

They say most engineers say you shouldn’t put more than 25kg per square metre in your loft. I suspect our over engineered old houses could support more, but again it’s an arse covering exercise from them.

I’ve used them and they are really solid, surprisingly so, I was sceptical too, how solid can plastic be? But they are plenty strong.


Up to you at the end of the day. But using timber will likely be more costly, more time consuming. And it adds weight more so than the plastic legs. It would most likely be stronger but how strong does it need to be. It’s going to rarely be under a dynamic load and unless you plan to put a home gym up there I highly doubt you’ll have problems with weight.

 

[dlockers]

I used this, far better than loft legs IMO since it creates a decent platform thats linked. Its quite quick once you get the first couple in place to act as a working platform

Raised Loft Boarding For Your Home | LoftZone UK

Our BBA-Approved raised loft boarding system saves money, helps the environment and increases safety, without invalidating new build warranties.

www.loftzone.co.uk

This looks awesome. Need to do some man maths.

If I read the spec correctly they’re covering their arse. The legs can support more, but the joists are probably more likely to fail before the legs if you overload them. So to save themselves from litigation “you said your legs could take 500kg but when I tried to store my car in my loft the roof caved in!!! Give me money!!!”.



They say most engineers say you shouldn’t put more than 25kg per square metre in your loft. I suspect our over engineered old houses could support more, but again it’s an arse covering exercise from them.

I’ve used them and they are really solid, surprisingly so, I was sceptical too, how solid can plastic be? But they are plenty strong.


Up to you at the end of the day. But using timber will likely be more costly, more time consuming. And it adds weight more so than the plastic legs. It would most likely be stronger but how strong does it need to be. It’s going to rarely be under a dynamic load and unless you plan to put a home gym up there I highly doubt you’ll have problems with weight.

Yeah that's a fair shout, I hadn't read the wording as closely as I should have.

I think my order is shaping up as:
* Bunch of cheap framing timber to add noggins to ceiling joists/avoid twisting
* Loft legs or loftzone (need to do man maths)
* New hatch
* New ladder
* 21 big boards
* Insulation
* 50MM PIR

Not sure how I get into this mess. My job at hand was the dining room

 

[Freefaller]

I would push some into the gap between the joists, 100mm is probably good. Then run a 200mm on top of that going perpendicularly to your joists.

Agreed with this.

 

[Mysterae_]

I used this, far better than loft legs IMO since it creates a decent platform thats linked. Its quite quick once you get the first couple in place to act as a working platform

Raised Loft Boarding For Your Home | LoftZone UK

Our BBA-Approved raised loft boarding system saves money, helps the environment and increases safety, without invalidating new build warranties.

www.loftzone.co.uk

That does look good, particularly their shelving system - keeps things off the floor promotes airflow underneath them.

Do you have any lateral sway with your install? I ask because even in their video when the installer stands up you can see the floor wobble a bit . Also surprised they don't lay the boards in a brick-like pattern for added strength, perhaps to save on cutting boards or to see where the beams are?

 

[Armageus]

They say most engineers say you shouldn’t put more than 25kg per square metre in your loft. I suspect our over engineered old houses could support more, but again it’s an arse covering exercise from them.

I’ve used them and they are really solid, surprisingly so, I was sceptical too, how solid can plastic be? But they are plenty strong.

I used loft legs to board out most of my loft. When combined with the OSB boards (I used the 1220mm ones from Wickes) it results in a strong floor that would take far more weight than I would dare to try.

I would push some into the gap between the joists, 100mm is probably good. Then run a 200mm on top of that going perpendicularly to your joists. Are you definitely going to use timber instead of loft legs? Seems like it would be a lot more work using timber. And does it really need to be super level?

I already had 100mm between the joists and then 170mm on top of that running the the opposite way. Some of it was badly laid and there were some areas that hadn't been covered, so got another couple of rolls of 170mm and rearranged/topped up whilst installing the loft legs.

Standard loft legs are designed for 100mm between joists and 170mm on top, leaving a small air gap below your boards. If you are going for 300mm insulation rather than 270mm then you'd need the larger Loft Legs XL, but that will obviously reduce your available head room in the loft.

 

[dlockers]

Top man, I didn't realise they did 170mm rolls. So 200mm+170mm+Loft Legs. With some framing timber to make me sleep easy at night.

 

[Mercenary Keyboard Warrior]

That does look good, particularly their shelving system - keeps things off the floor promotes airflow underneath them.

Do you have any lateral sway with your install? I ask because even in their video when the installer stands up you can see the floor wobble a bit . Also surprised they don't lay the boards in a brick-like pattern for added strength, perhaps to save on cutting boards or to see where the beams are?

I wouldn't say anything I have noticed. Its possible there is a little there but if so its minor
I remember when I added the first section, so 3 boards iirc it didnt feel like solid, but from memory as you join more its far more solid.

 

[Armageus]

Pro-tip if you do use loft legs - pre-fit all the screws into the bottom of them first (ideally before you take them into the loft), saves much frustration and lost screws trying to do it whilst in the loft.

Also possible relevant tip for someone - if you aren't fitting a loft-ladder/drop down style hatch, e.g. if your hatch just rests on a ledge around the opening, is to staple a large bag/plastic sheet to the back of the hatch, and then fill that with loft insulation - made a huge noticeable difference in my house as our hatch wasn't insulated at all.

 

[Freefaller]

That's a great tip for the loft hatch.

 

[dlockers]

This is the hatch I was considering:

Manthorpe GL250 Insulated Drop-Down Loft Access Door White 686mm x 856mm - Screwfix

Order online at Screwfix.com. Sleek, clean design with multiple catch locks for an excellent seal. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

I will glue some more insulation onto though I think.

 

[Mercenary Keyboard Warrior]

Thats like mine.
I keep meaning to add a load of pir offcuts I have to the back.
Sooner or later i am doing a bit more in the loft and will create an inner hatch then as well, so it creates like an airlock above the normal loft hatch

 

[Mason-]

Pro-tip if you do use loft legs - pre-fit all the screws into the bottom of them first (ideally before you take them into the loft), saves much frustration and lost screws trying to do it whilst in the loft.

Also possible relevant tip for someone - if you aren't fitting a loft-ladder/drop down style hatch, e.g. if your hatch just rests on a ledge around the opening, is to staple a large bag/plastic sheet to the back of the hatch, and then fill that with loft insulation - made a huge noticeable difference in my house as our hatch wasn't insulated at all.

I did read that about pre screwing.

But I didn’t do that and didn’t have a problem really. The Loft Legs have these nice guide holes for the screw. So I very rarely missed.

I’ll re emphasise again though, get a head torch! Was a blessing, you’ll be amazed how many times you create a shadow and can’t see f all.

Also I hope it goes without saying an impact driver or electric screwdriver is a must for this.

I ignored the advice on Loft Legs website and used spax 40mm m4 screws. They bite really well so maybe that’s why I didn’t have an issue without pre screwing.

 

[Semple]

Pro-tip if you do use loft legs - pre-fit all the screws into the bottom of them first (ideally before you take them into the loft), saves much frustration and lost screws trying to do it whilst in the loft.

Was about to say this.

I learnt the hard way after installing a few that they were just a ******* pain. So sat down in some comfort, nice and bright room without overalls/mask/goggles and just pre-screwed them. Was a breeze to install afterwards.

 

[Mason-]

Bread knife is good for sawing through the insulation btw.

 

[dlockers]

Right chaps - "big" order just gone into B&Q for:


n.b. I've only ordered 6 boards to get me going. I'll order the other 15 once I suss out the space I actually need/want.

I've also done a big Screwfix order including the new loft hatch.

Plan for the weekend is to get the loft "serviceable" but not insulated - as the plumber is theoretically arriving on Monday to start the big boiler and water tank installation.

That means...
1. New hatch
2. Rubbish bagged up
3. Boards up/laid to give them a place to work
fin

I also need to prep the Dining room (other thread) by chopping the boards. Unfortunately I couldn't find my brothers track saw so I'll be struggling with a regular circ (should be fine).

Wish me luck!