working out how many loft boarding packs in need please

[gazza12345]

hi all

i want to board my loft but being a bit thick with working out how many packs i need?


my loft is 8mtr x 8mtr and i'm looking at buying the packs from b&q.


One pack covers 1.2 square metres

Thanks

[lagi]

I make it 53 and a bit packs, you sure they are 1.2m per pack

[gazza12345]

hi ligi

there on the b&q website---

Length (mm): 1220

Width (mm): 325

Thickness (mm): 18

One pack covers 1.2 square metres

thanks

[lagi]

Well in case i am wrong, i calculated 8m x 8m = 64m divided by 1.2m (pack size)

[big-all]

you will need 24.6 widths so 25
8000 div by1220 =6.56

25x6.56=164div by 3 =54.6 or 55 packs with 7x 0.4 width planks and 1 full spare board

[gazza12345]

you will need 24.6 widths so 25
8000 div by1220 =6.56

25x6.56=164div by 3 =54.6 or 55 packs with 7x 0.4 width planks and 1 full spare board

Thats some maths there

Thanks for the help guys

[lagi]

Just seems like a lot of packs, hope there doing a deal on them.

[speed]

if you can get 8x2 floorboards up the loft hatch it will work out tons cheaper and be quicker to fit

[Inky Pete]

Just seems like a lot of packs, hope there doing a deal on them.

More to the point, how much is that little lot going to weigh???

Hope the joists are up to it!

[royaloakcarpentry]

If it is a trussed roof, they are not designed to carry an imposed load!!

If it is traditional cut and pitch roof, then someone has a lot more maths to do lol.

[ajrobb]

What is the centre spacing of the trusses?

Typically they are at 600mm intervals. You might need to trim EVERY board so the ends join on a truss. So the effective board length might be 1.2m rather than 1.22m. You'll want to stagger the joints.


I worked it slightly differently:
8 ÷ 1.2 = 6.66 (round up to 7)
8 ÷ 0.325 = 24.62 (round up to 25)

7 × 25 = 175 boards

There appear to be 3 boards per pack, so than means 175 ÷ 3 = 58.33, which rounds up to 59 packs!

Don't let the Council know what you are doing as insulation between trusses is not adequate for Part L Building Regs.

For a trussed roof, you might be better to run 4x2s along the bottoms of the 'W' part where the trusses are strongest and more 4x2s between them at 610mm centres (so you don't have to trim every board). This gives you a bit more strength and extra space for insulation. OK, so you only get to board the middle third of the loft, but it can't take much weight anyway. (That's what they did for my cold tank.)

[royaloakcarpentry]

What is the centre spacing of the trusses?

Typically they are at 600mm intervals. You might need to trim EVERY board so the ends join on a truss. So the effective board length might be 1.2m rather than 1.22m. You'll want to stagger the joints.


I worked it slightly differently:
8 ÷ 1.2 = 6.66 (round up to 7)
8 ÷ 0.325 = 24.62 (round up to 25)

7 × 25 = 175 boards

There appear to be 3 boards per pack, so than means 175 ÷ 3 = 58.33, which rounds up to 59 packs!

Don't let the Council know what you are doing as insulation between trusses is not adequate for Part L Building Regs.




For a trussed roof, you might be better to run 4x2s along the bottoms of the 'W' part where the trusses are strongest and more 4x2s between them at 610mm centres (so you don't have to trim every board). This gives you a bit more strength and extra space for insulation. OK, so you only get to board the middle third of the loft, but it can't take much weight anyway. (That's what they did for my cold tank.)

Nice advice for dealing with a trussed roof................nice to see you are more knowledgeable than TRADA when it comes to these matters.

That is very bad advice given in my opinion. You haven't even got a clue what truss design he may have, if it is a trussed roof. The OP hasn't a clue and you are advising what can't be done. I hope for his sake he doesn't pay any attention to your advice.

One big reason why I normally stay out of advice on boarding lofts as there are too many idiots about.

[big-all]

That is very bad advice given in my opinion. You haven't even got a clue what truss design he may have, if it is a trussed roof. The OP hasn't a clue and you are advising what can't be done. I hope for his sake he doesn't pay any attention to your advice.

One big reason why I normally stay out of advice on boarding lofts as there are too many idiots about.

very good points roc and very valid
we are all learning so we need to listen to others and rely on others to correct the mistakes that we all can make
as this is a diy forum we must expect the uninformed to be corrected by the knowledgeable hopefully with all avenues covered

[ajrobb]

Fair points. Yes, the topic of trussed rafters wasn't raised by OP. I really wanted to point out that boarding straight onto ceiling joists probably doesn't comply with Part L. OK, maybe it "can't be done" but that is how my house was built by Wimpey back in 1978 with 8m Fink trusses supporting a 280kg CWS tank. So, what does TRADA recommend?

[royaloakcarpentry]

Fair points. Yes, the topic of trussed rafters wasn't raised by OP. I really wanted to point out that boarding straight onto ceiling joists probably doesn't comply with Part L. OK, maybe it "can't be done" but that is how my house was built by Wimpey back in 1978 with 8m Fink trusses supporting a 280kg CWS tank. So, what does TRADA recommend?

You are welcome to look at the TRADA site and find out.

''Truss reaction loads'' and dispersion of them down a load bearing walls to the buildings foundations.............that is part of how a tank can be supported. It isn't sited mid span.