# Boarding Out Loft



## bluechimp (Dec 21, 2017)

So I have just moved in to a new house and the loft is boarded (poorly) directly onto the ceiling joists and as such there is 100mm max of insulation. This was adequate to regs at the time of build (Late 80’s), however now I want to reboard the loft properly.

Is overjoisting adequate, i’ve read online that it adds deadweight to already flimsy joists if not done properly or do I go for something like the loftzone kit that adds the 300mm height so I can add more insulation and create a vent etc.

The reason for this is I have loads of cracks in my upstairs ceilings where the joists have been overloaded, after all they are only designed to take a 25kg static load and to hold plasterboard up.

Would love to know your thoughts.

Cheers


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## c87reed (Dec 9, 2015)

I live in a new-build, house is now 4 years old. I haven't put a single thing in the loft; as you mention the trusses or ceiling joists are just not made to take the additional load. We have no ceiling cracks whatsoever but I'd bet we would have had we have put stuff up there.


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## rojer386 (Mar 15, 2008)

We are in our new build two years now. I boarded half of the loft last summer using loft boards and loft legs to raise the boards above the insulation (175mm iirc). 

We’ve had zero issues with ceiling cracks etc.


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## piston_warrior (Jul 25, 2012)

I live in a new build too and we also went for loft legs and boarded most of the useable space in the loft. There is an unbelievable amount of stuff up there including 20 or so full/half full paint tins and I have yet to see any sign of cracks on the ceilings.


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## garage_dweller (Apr 10, 2018)

We live in 20 year old house and I’ve part boarded the loft, there’s loads up there and non a single crack in the ceiling. 

Bought 300mm insulation recently to redo it as only 100mm at the moment. When that’s done I’ll use loft legs


Sent from my iPhone using Tapatalk


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## grunty-motor (Aug 11, 2016)

bluechimp said:


> The reason for this is I have loads of cracks in my upstairs ceilings where the joists have been overloaded, after all they are only designed to take a 25kg static load and to hold plasterboard up.


really need a drawing or a pic of the roof layout to know, but given your existing cracking issues, then loftsone kit wont add strength.

you would need to overjoist and to give bending strength (prevent sag) then they dont need a huge amount of screwing to the existing. However you will need to make sure the ends are supported too.

Is a simpler option just to board over an existing wall, rather than midspan?


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## stealthwolf (Sep 24, 2008)

I've got the loftzone kit. Makes the loft solid enough that two of us can walk around without any problems. Use it mainly for light storage. If I can lift it overhead, it goes into the loft.


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## bluechimp (Dec 21, 2017)

So after doing a bit more investigating into my new house, there have been several factors that have added to this, firstly my house is its joists and trusses on 600mm centres, so 15mm plasterboard should have been used but no, it has 12.5mm with no noggins. The boards are also not staggered so they have sagged and the crack has appeared.

I’m thinking of doing a project thread of all the work I am doing.


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## ollienoclue (Jan 30, 2017)

I have to top up the insulation in our place, I reckon there is only 100mm of insulation up there (the old glassfibre yellow stuff). What is the best stuff to put on top? Won't board it out as there as won't put anything up there.


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## stealthwolf (Sep 24, 2008)

Depending on how old the previous insulation is, it might be better to remove the old insulation and lay down fresh stuff. IIRC insulation thermal properties degrade over time. If you’re not boarding over the top, go for 200mm for second layer instead of 170mm. 

I bought Knauf stuff from Wickes as it came in rolls that were easy to cut (it had precut perforations), and was on offer for 3 for 2. It was a bit messy and can irritate the skin so you need PPE. Given that it can be difficult to get hold of a mask and goggles, you can get similar insulation that’s encased so you just roll it out. No need for PPE. 

The likes of celotex looks appealing but I read somewhere about how it’s thermal properties degrade very quickly (much quicker than wool insulation).


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## ollienoclue (Jan 30, 2017)

Thanks for that, I reckon the existing material is about 20 years old as the house was re-roofed and significantly extended around that time. I will just wait for some mental offer on the material because going into the loft at the minute would be unpleasantly hot.


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## spursfan (Aug 4, 2009)

the loftzone kit is very good, I did my loft a few months after i had new installation put in, the Loft Zone kit fit's nicely over the top and still leave a big enough gap for air circulation.
it is also very strong, so definitely worth the money
in my eyes.


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## spursfan (Aug 4, 2009)

ollienoclue said:


> I have to top up the insulation in our place, I reckon there is only 100mm of insulation up there (the old glassfibre yellow stuff). What is the best stuff to put on top? Won't board it out as there as won't put anything up there.


Have you searched online for a grant? i managed to get a firm that did all the work, ie..remove the old stuff and put in new stuff up to 300mm i think, by using the firm i got 35% discount and the 2 guys that did the work were there all day and wore all the protective gear, full hazmat and respirators, loft was sealed when they were working up there and all ols stuff bagged up and taken away.
well worth the money.:thumb:


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## ollienoclue (Jan 30, 2017)

spursfan said:


> Have you searched online for a grant? i managed to get a firm that did all the work, ie..remove the old stuff and put in new stuff up to 300mm i think, by using the firm i got 35% discount and the 2 guys that did the work were there all day and wore all the protective gear, full hazmat and respirators, loft was sealed when they were working up there and all ols stuff bagged up and taken away.
> well worth the money.:thumb:


It was something I was going to do next winter as it's an absolute mess up there (creeper that used to grow up the front wall of the house got in it). I don't mind lifting the old stuff up and bagging it up. It's only glass fibre after all, just makes you itch.

How much did your job cost roughly in the end?


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