Rebar to tie foundations together

[Souljim]

Hi all,

I’m taking down an old conservatory and extending it out to create a larger single storey extension. I’ve got some 25mm x 600mm steel bar to tie the new footings into the existing foundations and had a few questions. What size drill bit do I need? Is 26mm okay or do I need it to be slightly bigger (say 28mm) for the epoxy resin. I don’t want to buy an expensive resin gun to use it once either and I know you can buy some epoxy resins in a syringe that pre-mixes it. Any idea on which one’s best? Thanks

[PeterW]

Is this a requirement from building control ..? 25mm rebar is a little …. Extreme ..?? Should be able to use 12mm tbh as it’s only there for tension and differential movement that rarely happens. 

[Conor]

You usually go +2mm for resin setting.

 

[Tom]

I've just used 16mm rebar for our footings, 18mm hole for the resin. All 200 of them.

[markc]

10 hours ago, Souljim said:

Hi all,

I’m taking down an old conservatory and extending it out to create a larger single storey extension. I’ve got some 25mm x 600mm steel bar to tie the new footings into the existing foundations and had a few questions. What size drill bit do I need? Is 26mm okay or do I need it to be slightly bigger (say 28mm) for the epoxy resin. I don’t want to buy an expensive resin gun to use it once either and I know you can buy some epoxy resins in a syringe that pre-mixes it. Any idea on which one’s best? Thanks

Morning, Sounds like you are talking about shear connectors to keep the two slabs aligned. Assuming this is the case, drill a couple of mm oversize and resin in, then slid a piece of plastic tube over the other end before the pour to allow movement. But 25mm is still a very big bar.

[markc]

Oh and you dont need a resin gun, plastic or glass capsules, point of end of bar and spin in with a drill