Can I Join Two Pieces of Timber to Make One Floor Joist?

[Williamraff]

Hi Folks,

As above... would it be acceptable to Building Control to join two lengths of 200mm x 50mm C16 floor joists to make one joist?

I had intended converting a 5m x 3m area of the loft but I have now decided to run a wall plate around the entire loft; this will require a 4.3m joist to span between the front and back elevation.

This means that the timbers I have are too small hence the above question.

Any advice or comments will be gratefully received.

Regards,
Will.

 

[tony1851]

It's not clear what you want to do. Do you mean double the joists up to make a 100x200? or what?

 

[big-all]

if you increase the span by say 50% the timber size will need to be around twice the size to give a similar strength

 

[Williamraff]

It's not clear what you want to do. Do you mean double the joists up to make a 100x200? or what?

Hi, to clarify, the length of joist I require is 4.3 metres, my timber is currently in 3 meter lengths. My question is - is it acceptable to bolt two 3 meter lengths together to make a joist 4.3 metres long?

Thanks,Will.

 

[Williamraff]

if you increase the span by say 50% the timber size will need to be around twice the size to give a similar strength

Hi, I am using oversized timber, according to the Building Control beam calculator - 200mm x 50mm is sufficient to span 4.3 metres.

Thanks,Will.

 

[tony1851]

It's not clear what you want to do. Do you mean double the joists up to make a 100x200? or what?

Hi, to clarify, the length of joist I require is 4.3 metres, my timber is currently in 3 meter lengths. My question is - is it acceptable to bolt two 3 meter lengths together to make a joist 4.3 metres long?

Thanks,Will.

Technically that could be done, as long as the fixings were adequately designed to take the shear stress - not very easy to calculate and detail.. The joist also might twist a bit.

It would be botch - better to get a joist of the correct length.

 

[Jackrae]

By the time you've bought either steel fish plates of sufficient length (2 per joint) or sufficient timber fish plates you'd be cheaper to buy new timber of the correct length. You can use your 3M lengths for cross noggings or wall plates etc

 

[cjard]

or take it back and use it as credit against the 4.3m

 

[Williamraff]

By the time you've bought either steel fish plates of sufficient length (2 per joint) or sufficient timber fish plates you'd be cheaper to buy new timber of the correct length. You can use your 3M lengths for cross noggings or wall plates etc

Yes I agree, I have thought better of it since my original post. I will be opting for the correct length timber, it was just a thought.

Thanks for the responses anyway .

Regards,Will.