Loft joist and boarding question

[DrEvil]

Background:

I have a mid terrace 1930 build house. c. 31' Long x 17'6" wide.

I've got some people coming to in to lay insulation (it's free) - they have said they will lay 10" worth but I also want to do some boarding for storage purposes.

The house currently has 4"x2" beams laid along length of house with slight offcentre/overlap at the middle of the house. Beams laid on short side These are spaced at c. 12.5"

I also have the occasional cross-beam going across width of the house - again 4"x2" beams laid on short side butat variable spacing. Guesstimate first one at c. 1.5m from front, then another 1.5m to next, then 5m to next, and finally then 2m to back.

Finally I have two short cross-beams 4x2 laid on wide side which support beams going to the roof structure.

I hope you are still with me and apologise for naff description or terminology!!!!!

So what I want to do:

I want to board some of it, probably the middle section and have some questions:

1. Am I right in assuming the best way to do this is to put more cross beams and then board (this seems right from searches)?
2. Should I continue to lay cross beams of 4x2 or should I use different sized wood (wider etc - is 2" wide going to be ok to board on?)
3. Is there a type of wood I should use?
4. Is there any reason I shouldn't lay them in a line and not offset as my base beams are (laying in line will mean its easier to board.
5. What wood should I use as the boarding - chip or mdf or ply and what size (I've seen 8'x2' seems to be consensus).
6. Would I lay this along the cross beams or across the cross-beams
7. What interval should the cross-beams be laid at (kind of dependent on the answers to 5 and 6)
8. In terms of attaching the cross beams - my existing ones seems like they've had two nails through the side into the base beam - would it be better to drill and screw?

9. Any other tips?????


Thanks

 

[DrEvil]

Not a whole lot of replies, but I tried several more searches and found this //www.diynot.com/forums/viewtopic.php?t=146949 which answered many of my queries.

Thought I would cross post in case it helps future people find the right threads.

I'm also planning to lay the crossbattens with no overlap, lines at 2ft centred gaps, going for 4x2 treated and prob 12mm ply or chip - depends on price!

 

[Static]

Sometimes a post or two slips the nets..

1. Am I right in assuming the best way to do this is to put more cross beams and then board (this seems right from searches)?
2. Should I continue to lay cross beams of 4x2 or should I use different sized wood (wider etc - is 2" wide going to be ok to board on?)
3. Is there a type of wood I should use?
4. Is there any reason I shouldn't lay them in a line and not offset as my base beams are (laying in line will mean its easier to board.
5. What wood should I use as the boarding - chip or mdf or ply and what size (I've seen 8'x2' seems to be consensus).
6. Would I lay this along the cross beams or across the cross-beams
7. What interval should the cross-beams be laid at (kind of dependent on the answers to 5 and 6)
8. In terms of attaching the cross beams - my existing ones seems like they've had two nails through the side into the base beam - would it be better to drill and screw?

9. Any other tips?????

1. Yes
2. 4x2s will be fine
3. C16 timber.. cheap and chearful, this isnt a structural addition to the loft..
4. Laying parallel makes it far easier to board, but if you want to lay them in a random patern.. go for it..
5. Cheapest you can find.. around the hmm 18mm thickness should be fine.. its just for light storage
6. Lay across.. most big sheds sell loft boarding, normally its about 1200mm long so spans over 2 joists..
7. 600mm maximum, could do 400mm.. best to see what boarding your gonna use and set the joists so you dont need to cut the boards down.
8. Either.. your existing "cross beams" are probably ceiling binders that help keep the ceiling joists deflection down to a minimum so leave them be..
9. Others may have..

 

[DrEvil]

Sometimes a post or two slips the nets..

1. Am I right in assuming the best way to do this is to put more cross beams and then board (this seems right from searches)?
2. Should I continue to lay cross beams of 4x2 or should I use different sized wood (wider etc - is 2" wide going to be ok to board on?)
3. Is there a type of wood I should use?
4. Is there any reason I shouldn't lay them in a line and not offset as my base beams are (laying in line will mean its easier to board.
5. What wood should I use as the boarding - chip or mdf or ply and what size (I've seen 8'x2' seems to be consensus).
6. Would I lay this along the cross beams or across the cross-beams
7. What interval should the cross-beams be laid at (kind of dependent on the answers to 5 and 6)
8. In terms of attaching the cross beams - my existing ones seems like they've had two nails through the side into the base beam - would it be better to drill and screw?

9. Any other tips?????

1. Yes
2. 4x2s will be fine
3. C16 timber.. cheap and chearful, this isnt a structural addition to the loft..
4. Laying parallel makes it far easier to board, but if you want to lay them in a random patern.. go for it..
5. Cheapest you can find.. around the hmm 18mm thickness should be fine.. its just for light storage
6. Lay across.. most big sheds sell loft boarding, normally its about 1200mm long so spans over 2 joists..
7. 600mm maximum, could do 400mm.. best to see what boarding your gonna use and set the joists so you dont need to cut the boards down.
8. Either.. your existing "cross beams" are probably ceiling binders that help keep the ceiling joists deflection down to a minimum so leave them be..
9. Others may have..

Cheers, really really helpful response.

BTW, have phoned local timber, he suggested to use 22mm T+G moisture resistant chip (in 8'x2') if 600mm centred or 18mm if 400mm centred. So either more joists or slightly more expensive boarding (much of a muchness really, but suppose more time if more joists).

 

[Static]

Cheers, really really helpful response.

BTW, have phoned local timber, he suggested to use 22mm T+G moisture resistant chip (in 8'x2') if 600mm centred or 18mm if 400mm centred. So either more joists or slightly more expensive boarding (much of a muchness really, but suppose more time if more joists).

Fairly good advice from a timber yard.. would go with moisture resistant actually as its in the loft.. less change it will warp in the winters..

 

[Deluks]

8. In terms of attaching the cross beams - my existing ones seems like they've had two nails through the side into the base beam - would it be better to drill and screw?

Yes! Pilot and screw, min 90mm screws put in at an angle.
Pounding nails into 4x2 may cause cracks to appear in the ceiling. Or make any existing ones worse.

 

[ajrobb]

There will be a possibility of condensation if you board tightly over an insulated humid room (bathroom). Unventilated mineral wool insulation should be protected with a vapour proof layer on the warm side. I don't know how effective gaps between wooden floorboards would be in ventilating the insulation.

 

[DrEvil]

There will be a possibility of condensation if you board tightly over an insulated humid room (bathroom). Unventilated mineral wool insulation should be protected with a vapour proof layer on the warm side. I don't know how effective gaps between wooden floorboards would be in ventilating the insulation.

Boarding area will be over hallway and part of two bedrooms, not over the bathroom (though will be insulation over the bathroom).

 

[DrEvil]

8. In terms of attaching the cross beams - my existing ones seems like they've had two nails through the side into the base beam - would it be better to drill and screw?

Yes! Pilot and screw, min 90mm screws put in at an angle.
Pounding nails into 4x2 may cause cracks to appear in the ceiling. Or make any existing ones worse.

Ok, this confused me for a bit as I was assuming I would pilot and screw vertically down through the top cross beams into the rafter - (therefore need a screw which covers 4"for the cross beam and say 2" into the rafter or c.150mm), so 90mm confused me a little.

But I am right in thinking that you are suggusting that I would drill through the side of the cross beam and at an angle into the rafter.

[Don't mind doing either, just happy to clarify and take recomendations!]

Thanks all btw - really helpful responses.

 

[Static]

At an angle is easier and will need shorter screws.. Deluks speaks sound sense..

 

[DrEvil]

Superb, thanks for the clarification!