Timber Frame Self Build

prewtna

Just lodged planning today for a detached dwelling. Hoping to go the self-build route and possibly using a timber frame construction. Would really value people experience / input.

Am drawn to timber frame - as i understand it, it has less affect on Carbon footprint etc and would speed up construction on site - provided one has all the windows, roof etc lined up immediately upon installation of the timber frame.

So, some queries:

from my research one can provide a concrete screed to the upper floor (provided the floor strcture is designed to take it) - does this actually 'solve' perceived acoustic issues with impact and other noise types through the floor? Have any of you done this?

I loathe cavity wall construction (if im honest - blockwork in general) - very messy, hard to supervise etc. Therefore i would prefer not to use any blockwork - even for a simple external leaf - Have any of you placed EWI to a timber frame construction? What was your experience on site and indeed the experience thereafter?

Would anyone have any data (even heresay) on cost comparison between a plain old blockwork house versus timber frame - i do realise that is a very open-ended question with many variables.

If you have built a timber frame house, how much wiring was done in the walls in the factory? i am personally not concerned about designing and deciding on socket locations etc on drawings and driving on from there, however, my better half wouldnt be the best at reading drawings so i am concerned there may be a lot of changes to that kind of thing on site. I suppose one of the benefits of a blockwork house, would be that could be decided on a more adhoc basis - given how long blockwork would take to rise etc.

This thread may well grow legs as i consider roofing etc, but for now, some comments on timber frame would be greatly appreciated.

thanks

sydthebeat

EWI isnt suitable for Timber Frame builds

bfclancy

i went timber frame with block outer leaf back in 2018. cost is probably more or less same as normal block house.speed is the big factor. we went from groundworks to living in the house in the space of seven months and no major drama or hounding of tradesmen. all wiring and plumbing (except toilet location as pipes went into floor) done on site when frame was erected. mine was bungalow so didn't have to consider first floor screed. the frame will most probably come insulated so i wouldn't be worrying about ewi. you could clad it in something other than block i'm sure. section of mine is clad in zinc which is fixed to 50mm battens fixed directly to frame, same could be done with cement board or any other cladding.

BryanF

Screed will help, sit with supplier and arch and review/agree db expectations and penalties! and watch them squirm

Re ewi, I have gutex in places outside of the racking board/breather membrane in my timber frame extension. You won’t need a lot of it if you detail the timber wall structure correctly. Deciding on rain-screen or whatever on the outside is the challenge.

Re wiring depends on the type/level of offsite fabrication. Normally there is a service cavity, so services can be planned/installed & changed! on site.

Re deciding anything ‘on an adhoc basis’ - that is IMO fundamentally going to slow things down, and have the potential to have knock-on that impact design and quality. Plan everything to the last detail or pay someone else to.

Edit: I commend your interest in low carbon materials. Perhaps Consider how you might reduce other material inputs such as concrete, I went with an insulated formwork system, which also reduced excavation and hardcore.

prewtna

bfclancy wrote: »

.....cost is probably more or less same as normal block house........ all wiring and plumbing... done on site when frame was erected. .... section of mine is clad in zinc which is fixed to 50mm battens fixed directly to frame, same could be done with cement board or any other cladding.

thanks for your note bfclancy. i have spoken with a couple of timber frame companies at trade shows and they did say cost was similar to blockwork but i would always take that with a pinch of salt. glad to hear they werent telling me porkies. i presume you shopped around somewhat - without naming names, was there much price variance in frame suppliers?

indeed on the wiring etc, i am not pushed either way - so good to know you did it all post frame install. as i said i would happily (and will) design it to the nth prior to install, but i dont want to railroad my better half into it either - as she struggles with spatial awarenes and visualising outcomes from drawings.

funnily enough i have two elements of our design notionally with metal cladding also. i presume the zinc area was relatively small, did you have any difficulty getting a contractor for the zinc? i have a metal roof proposed too so perhaps that will sweeten it somewhat for them.

Cement Board - indeed an option (presumably with an applied self coloured render) but i would be concerned about its long-term durability and cracking at the joints.

prewtna

sydthebeat wrote: »

EWI isnt suitable for Timber Frame builds

thanks sydthebeat. ya im looking through various suppliers and there doesnt seem to be a mention of it really. is that because of the diagram in TGD-L which indicates masonry outer leaf?

i wonder though, given TGDs are exactly that - if it could be demonstrated by calculation that EWI eliminated risk of interstitial condensation and of course achieved the required u-value - would that fly from a compliance point of view?

Perhaps there is something i am fundamentally not understanding about timber frame construction which requires the cavity? if there is just shout and ill drop this line of questions!

prewtna

BryanF wrote: »

Screed will help, sit with supplier and arch and review/agree db expectations and penalties! and watch them squirm

Re ewi, I have gutex in places outside of the racking board/breather membrane in my timber frame extension. You won’t need a lot of it if you detail the timber wall structure correctly. Deciding on rain-screen or whatever on the outside is the challenge.

Re wiring depends on the type/level of offsite fabrication. Normally there is a service cavity, so services can be planned/installed & changed! on site.

Re deciding anything ‘on an adhoc basis’ - that is IMO fundamentally going to slow things down, and have the potential to have knock-on that impact design and quality. Plan everything to the last detail or pay someone else to.

Edit: I commend your interest in low carbon materials. Perhaps Consider how you might reduce other material inputs such as concrete, I went with an insulated formwork system, which also reduced excavation and hardcore.

Thanks BryanF.

I find db ratings are a bit of a dark art really which are hard to translate into real life examples. i will be my own architect (its what i do - but my projects are large commercial ones so domestic is a bit of a mystery to me).
i am squirming already at the thoughts of getting the upper floor spec wrong. i am happy enough with some noise transfer up and down through the floor, but most people who have built one-off house in the last 20 years have gone with hollow-core, it would be other people expectations that i am trying to temper somewhat. as far as i can see it would be impossible to achieve the same acoustic result in timber frame even with the screed. in reality its just a detail i will have to work out with suppliers.

when you said deciding on rainscreen is the challenge - what did you mean?

as mentioned in other responses - i will be desiging it to the nth so am quite hopeful there will be little adhoc stuff - but you know yourself, the first casualty of war is the plan!

thanks for your comment on the carbon side of things. i guess part of my motivation is that due to the type of projects i ordinarily work on, my professional carbon footprint is probably massive - thousands of tonnes of concrete gone into buildings over the last 10 years. i have tried and failed to get clients to consider other options. so i want to do what i can on this one! As regards the foundation - indeed your comment on the insulated formwork is well made. we are fortunate in that the ground is good so our options are broad. how did the insulated formwork compare costwise versus others in your case?

bfclancy

not much price variance. got lucky with zinc installer as he had a large job that was delayed so he could fit me in at very short notice, i can pm you the details

BryanF

Beat of luck with your build, keep us updated on how you get on.

johnnyfruitcake

Hey, any updates on how this went?
Looking at timber frame with block outer leaf myself.

BryanF

Prewtna was talking about block work in a more recent post.

Prewtna,
Are you still being ‘your own architect’?