Timber frame help

[johnnyb]

Can anybody point me to a good guide on timber framing. Not the oak stuff just a small extension I'm planning. It's just all the details I'm interested in. How deep for the foundation? (Piece of string i know) attaching the frame to the footings. What's typical at the bottom. Timber sizes(2×4). Insulation depth. Osb outside ? All wrapped in a breathable membrane? Which one? Am i best building stick by stick (American style) or modular panels(euro style). Questions questions.

 

[Rob Platt]

TRADA
all the best
rob

 

[MikeG.]

You need an architect.

There is a great book on timber framing by TRADA, called (believe it or not) Timber Frame Construction.

 

[MikeG.]

.......... Osb outside ?...........

No. No, no, no. This is going to one day be one of the biggest scandals in construction. OSB should be on the inside.

 

[johnnyb]

Thanks for the replys. When I've done stuff like this before( without much knowledge) I've put stainless studs into the concrete then 2 courses of brick with the studs in the holes of the brick. I've attached a stud to the top of the bricks( with bolts) then levelled upthe frame that goes ontop using Packers if needed. Three studs to go around corners. Etc etc. An architect may be Overkill for this. I could build it in blocks in 3 days. It's just I'm a joiner and want to do it properly in timber.
I'll have a look at the book you guys mention. But if anyone can elaborate without me having to decipher it would be much appreciated.

 

[Sawdust=manglitter]

If its only a small-ish extension then so long as you have a rough sketch with dimensions and details of the roof (trusses/cut roof with ridge beam/flat roof joists) then that should be sufficient for a structural engineer to design for you. I'm a structural engineer myself... we would design the stud sizes/spacing, size/spacing of nails into the OSB, location of internal racking walls, type/spacing of soleplate fixings, lintel sizes etc etc. But yes, we often recommend the TRADA 'Timber Frame Construction' book to timber frame contractors or self builders. Hope this helps, and good luck

 

[MikeG.]

Straps over the sole plate and screwed to the inner face of the plinth is the proper way to do it. If you build studs into the plinth you pierce the DPC, and it is frankly more difficult, time consuming and expensive. Ideally, you bed the DPC first, then bed a plate on top of that with housings for the straps. Then you fix the timber frame on top of that plate, so end up with 2 sole plates, one on top of the other. It's much easier to level the initial plate if it isn't part of a big timber frame, and it's difficult to lower a timber frame onto a bed of mortar without shoving mortar all over the place in the process.

If this is an extension, then it needs to comply with regulations. 95mm framing can only comply with the requirements of Part L if you add insulation across the inner face of the studs in addition to that which is between the studs. This doesn't apply with 145 studs. Breather membrane on the outside of the frame, OSB on the inside, and don't forget a battened-out zone outside the studs if you are fixing a cladding direct to this leaf of the wall (obviously, some people build a brick outer skin). Don't forget also that your plinth requires a cavity (100mm), and making that work with a timber frame requires some thought.

Any more than that and I'll send you a bill!

 

[johnnyb]

Honestly for that quality of info send me your invoice!
I guess the trada book will have some plinth cross sections to look at.
Interesting point about insulation I'm guessing insulated p/b is the best way to get over that.
Battening I'm guessing is to make sure the breather membrane can well...breathe! In a manner to suit your cladding( horizontal/ vertical)
The strapping on the inside face will be similar to the straps that hold a roof plate on and fixed in a similar way?
Cladding although visually important is the easy bit i guess.