Can I splice 2x4 like this?

[smp50]

I have a lot of 2.4m lengths of 45mm x 95mm treated C16 stuff which I want to use to build a shed floor frame/base. On top, they will have 18mm OSB3.

The shed is to be about 4m x 3.5m so none of the timber is long enough in either dimension. Is there a decent enough way to splice this stuff together - some kind of half lap joint plus sandwiching more wood onto either side of each joint and screwing (or even bolting) through all three pieces?

Or instead of a half lap, is there any value in making an easier cut like this and screwing along the arrow lines?

Needless to say, the positions of these joints (whatever form they take) will be positioned over a support (block, adjustable riser, whatever I use).

Bear in mind that I'm not very neat with a hand saw and my only power saw is a sliding mitre.

EDIT:
Or is the proper thing in this situation to make multiple pieces of frame and then join them together? Like this:

 

[Doggit]

A half lap joint using gorilla glue would be better, but truth be told, neither solution is that sensible.

 

[Tigercubrider]

Could you not start by laying out the osb and screwing the timber as braces to the osb? Anywhere that there is a join, add an extra length of timber right next to the timber that is being joined.

Then flip it over.

It uses more timber than if each was just joined, but if you have loads of it.....

 

[smp50]

Could you not start by laying out the osb and screwing the timber as braces to the osb? Anywhere that there is a join, add an extra length of timber right next to the timber that is being joined.

Then flip it over.

It uses more timber than if each was just joined, but if you have loads of it.....

In practice I'll have to make the frame first but then of course put the OSB on it right away, yes. I don't have a large enough flat area to lay out the OSB nicely like that, it would be a struggle to get it all lined up neatly.

If I overlap/sandwhich the joints, surely just going say 300mm either side is sufficient? That's enough to get a whole lot of fasteners through on either side.

 

[Tigercubrider]

If it was me I would tend to go for a metre if I had the wood but I over engineer everything but probably yes

Weigh up the hassle of fixing it if it goes wrong. Do not have osb joints and timber joints overlapping

 

[chappers]

essentially yes you can but try to make the scarf joint longer so the you can get 2 or 3 fixings through it preferably from each side with glue in the joint.
Personally I would use PVA over PU glue as it actually bonds into the wood

 

[John D v2.0]

I'm no structural engineer but I know that you can only rely on standard screws for clamping not shear.
Depends on the loads, but personally since 2 by 4 is only good to span around 2m, I'd follow your idea of making separate spans supported on intermediate blocks. You could use trimmers as you seem to have drawn, but you then have to watch your load as well as deflection in both directions. Better to build a sleeper wall at mid span and just go two spans either side.
Hope this helps!

 

[John D v2.0]

PS no need to be neat with your saw, this is classed at "first fix" anyway!
My top tip would be to clamp it well and make sure your eye, elbow and shoulder are near enough in line with the cut you're making.

 

[big-all]

you will need around 30 timbers for the verticals
have you more than that to use up??

 

[Roger928]

A 35 degree cut would be better and splice the sides with 13mm wbp plywood about 500mm long.. Glued on with cascamite and nailed with 40mm ribbed nails.
The nails would be about 20mm from the edge and about 70mm apart.

 

[chappers]

Having re read the OPs post, as this appears it will be a suspended floor I agree with Roger best to sister up something alongside the joint.