Hi
I really need some advice for what kind of restraint straps I should use to increase the joist strength for a roof garden on a summerhouse, that's being built right now.
The joists are 38mm x 63mm and the unsupported span is just under 2400mm from front to back. The joists are in the upright position, as they are supposed to be, and there are 4 joists that don't have any support, except at the ends. I might use joist hangers to secure the joists, or extra secure them, to the outer frame of the roof structure and maybe angle brackets and nail plates to secure the top frame as a whole to the four walls.
The same wood will be used for a small number of noggins and the joists will be faced with topside and underside boards before the garden structure is added. One of the questions I have is do I need to strengthen the joists at all?
The unsupported area is about 5.7 square metres and the max weight of the wood, an additional roof light and a rain-laden roof garden may exceed 100kg.
Maybe I've answered my own question.
Would I need to span the entire length with the straps, or just the central section – middle 600mm, 1000mm or 1200mm? What about two 1000mm straps, on either underside, for each joist?
Heavy duty or light duty straps?
Could I strengthen the sides/upright face of the joists instead, so I can leave the underside free for fixing the ceiling boards/plaster board/tongue & groove?
Would builders' band be sufficient? I wouldn't have thought so, but it would be ideal and cheap too.
Ideally I'd love to find some cheap galvanised steel strip, cut it to size and drill lots of holes myself, to save some money.
A lot of questions, so thanks for any help anyone can give.
Cheers.
I really need some advice for what kind of restraint straps I should use to increase the joist strength for a roof garden on a summerhouse, that's being built right now.
The joists are 38mm x 63mm and the unsupported span is just under 2400mm from front to back. The joists are in the upright position, as they are supposed to be, and there are 4 joists that don't have any support, except at the ends. I might use joist hangers to secure the joists, or extra secure them, to the outer frame of the roof structure and maybe angle brackets and nail plates to secure the top frame as a whole to the four walls.
The same wood will be used for a small number of noggins and the joists will be faced with topside and underside boards before the garden structure is added. One of the questions I have is do I need to strengthen the joists at all?
The unsupported area is about 5.7 square metres and the max weight of the wood, an additional roof light and a rain-laden roof garden may exceed 100kg.
Maybe I've answered my own question.
Would I need to span the entire length with the straps, or just the central section – middle 600mm, 1000mm or 1200mm? What about two 1000mm straps, on either underside, for each joist?
Heavy duty or light duty straps?
Could I strengthen the sides/upright face of the joists instead, so I can leave the underside free for fixing the ceiling boards/plaster board/tongue & groove?
Would builders' band be sufficient? I wouldn't have thought so, but it would be ideal and cheap too.
Ideally I'd love to find some cheap galvanised steel strip, cut it to size and drill lots of holes myself, to save some money.
A lot of questions, so thanks for any help anyone can give.
Cheers.
