I've just written a free extension to the Sketchup 3D app which aims to help novice builders create the frame for garden offices, workshops, studios (and "Tiny Houses") up to 30m2 floor area using the Segal-method of post and beam timber framing.

http://extensions.sketchup.com/en/content/segal-method-timber-frames

It can create mono-pitched (shed) and dual-pitched (gable) roofs with specified maximum/eaves heights for avoiding the need for planning permission in the UK. Rafters can be solid timbers or engineered timber I-beams. Metal fixings are included in the model, such as M12 bolts and truss clips. Floor joists at 400mm or 600mm centers can be added, as can wall studwork.

It also saves out a spreadsheet listing all the components used, as standard length timbers, etc. to make it easier to cost & order the parts.

It is still an early version of the extension, and I'm sure there is lots of room for improvement, so I would dearly love to hear any feedback - positive or negative! Ideas for new features, things I should be doing differently, etc.

I think I've made a mistake by having the floor joists resting across the sills of the bents (and having the bent tiebeams underneath the topplates) ? It does simplify the design (e.g., no need for joist hangers) but it drastically reduces the headroom, which is a big problem if you are building under permitted development and the eaves height can't be more than 2.5m :(

Many thanks

You could get around using joist hangers by sitting the floor joists on a batten which is fixed to the side of the green cross beam. Just make sure the batten ( or other size timber depending on space) is properly fixed with glue and mechanical fixings directly below each joist. This was my workaround when I encountered the very same trying to make a suspended timber floor within permitted development . It might not pass building control but I wasn't fussed.

I have a model on my laptop which I'll post up when I get a chance.

I look forward to having a look at your extension.

Posted By: djh

Posted By: MikCYou could get around using joist hangers by sitting the floor joists on a batten which is fixed to the side of the green cross beam.

I don't understand. Yes, you could sit the joist ends on a ledger beam that was lower than the cross beams, but how do the joists cross the intervening cross beams?

Ledger beam, that's a better description. The joists would butt up against the intervening cross beams, so lots of small joists rather than one long one.

Would there be any issue with that approach?

Posted By: Peter_in_Hungary

Posted By: MikCWould there be any issue with that approach?

Extra work/cutting and extra materials (2 x ledger beam per joist)

true, but cheaper than joist hangers and quicker too, i would have thought

Posted By: sheffieldnickand very quick to fit with the recommended 3.75x30mm square twist nails.

Sorry, bit off topic but while we're here, anybody know if those can be put in with a nail gun?

or a spare pair of eyes

Another question: my extension currently uses the same size of beam for the bent sill (supports weight of floor + building contents) as it does for the bent tiebeams (under tension only, to stop the roof from spreading?).

Can I get away with never having more than 100x47mm for the bent tiebeams? I don't know if I'm reading this table correctly, but I think for C16-graded timber under tension parallel to the grain, it should take 3.2N/mm2 so that is 15kN / 1500kg ? That would allow for cheaper tiebeams, as well as (slightly) more headroom.
http://www.roymech.co.uk/Useful_Tables/Timber/Timber_design.html

Thanks

Posted By: sheffieldnicksoftwood deforms under compressive point loads

Very true. One of my carpenters accidently hit the outside of my front door with a hammer. Big dent. Fortunately he suggested putting a patch over it of damp kitchen towel, held in place by duct tape. No dent visible after that. I've just done the same - dented a door jamb by accidently trapping an object as the door was closed.

Bump for this thread

Nick, did you see my message to you on July 4th? The proposal still stands, especially now I'm ready to finalise a design and start building.

I must download this, thanjs