Using bolts and connectors instead of nails

[garyo]

I'm considering using bolts, square spreader washers, and sandwiched timber star connectors to join my rafters to my joists.

Is this done very often - do the majority of cut roofs still go up using skew nails? When joining 150mm section rafters with 195mm section joists, how many M12 bolts should be used?

Thanks

Gary

 

[HERTS P&D]

What are you doing?

Andy

 

[noseall]

Adequate connection between rafter bottom and joist end can be achieved with two 100mm 6's screws or even nails. It is just as important to fix both elements to the wall plate in similar fashion but with say 75mm 5's.

We usually fix through on an angle so that the 100mm fixing does not protrude through both sets of material. A 100mm fixing fixed straight would protrude through about 5mm.

Bolts may encourage splitting at the ends, particularly if you need two.

 

[^woody^]

We've been using nails for this since before the middle ages

Bolts and star washers are unnecessary and serve no purpose for this connection

 

[garyo]

Herts - it's a rear extension, double pitched roof with hip end, ~4M span, ~2M height.

Woody - the reason I asked is that I've read about their use in this junction on the old TDA designs in the 50's / 60's. You still see the star couplers in merchants today - where are they used?

Thanks

Gary

 

[theoldun]

Woody - the reason I asked is that I've read about their use in this junction on the old TDA designs in the 50's / 60's. You still see the star couplers in merchants today - where are they used?

Bulldog toothed timber connectors were used in every connection on the old TDAs back in the 50s. Every member was bolted together with a bulldog connector between every piece of timber. Also used to join two timbers together to form a bressmur. Also used to bolt ceiling joists to rafters in a raised tie ceiling. If you wish to use them in your situation, then do so, but they are well over the top of requirements.
Will post tomorrow and tell you best and easiest way way to pitch. Will also answer your question ref layboards etc.
Regards oldun

 

[garyo]

Cheers guys - I'll think I'll use screws/skew screws then.

I'll also go buy a more up to date roofing book that doesn't fill my head with crazy ideas!

 

[^woody^]

If you are not making trusses, then you don't need bolted connectors as in the TDA guides .... which are probably outdated anyway

 

[^woody^]

You still see the star couplers in merchants today - where are they used?

Star connectors are still used where timbers need to be joined, and loads need to be shared between them (shear loads) and some assistance needs to be added to aid normal friction - ie to prevent some sliding

Nails do the same job in terms of shear/friction, but star connectors give the friction support to the two timber pieces, which a bolt alone wont give