Scarf Joint

[parauk]

Hi all

Help needed Please

I have been told to use a scarf joint to join 2 joist`s together (wood being 8"X3") and use Dog Washers and coach screws to secure a metre long plywood for strength either side of the joint.

So where do i put these dog washers? On the outside that they bite into the plywood?

Chris

 

[Harbourwoodwork]

Dog washers have spikes on both sides that squash into the wood when two pieces of wood are bolted together. They are very good and stop the timber scissoring. I wouldn't give you much chance of squashing them into plywood but are fine into pine. I would be interested in seeing the detail on that joint. Who was it specified by? I've done this job before and just bolted the new section side by side on property waiting for a proper re furb. You can't beat running a new length in. These sound like quite hefty joists.

 

[ladylola]

If I'm reading this correctly it seems to me that the two timbers are being jointed end to end (presumably with a proper joint and not a simple butt) and the ply is acting as some sort of "gang nail plate". As said the dogs or timber connectors won't go into the ply too well. I've done similiar but have screwed the ply and glued it too if I recall correctly but have only used the connectors if I were fixing the two 8x3"s side by side.