Green Larch Timber Frame

[ucoulddoit]

Found an interesting recent publication on google about using green softwoods in construction including post and beam, which might be of interest to others. It promotes using larch which is predicted to be widely available due to felling because of .... (can't remember the name of the bug/virus). Just needs a bit of innovation in the supply chain to get people to start using it in decent quantities.

 

http://www.bc.bangor.ac.uk/news-and-resources/news/documents/WelshSoftwoodsinConstructionReportNov13.pdf

 

Andrew

[agg221]

Thanks for all the comments. The columns are 200 x 200 which is pretty chunky for a total roof area of about 26m2.

 

Andrew

 

Ah, not quite as big as I thought - my initial impression was more like 10" square. I would probably have guess that you needed a 6" post, but then thinking about it I'm used to box frames with studs which carry some of the load.

 

Alec

[corco2000]

ucoulddoit. that is very impressive.great work. amazed you needed planning.

you mind if i ask how thick slab is? and what mill and saw you used. thank you

[difflock]

very very impressive work, but as commented above looks over-engineered, to me waaaay over-engineered, but then the wind loading is a key factor.

Proper jealous I am.

PS

Especially liked the tidy pads with (very long?)hold down threaded rod.

BUT!

the Uncle Tony in me cannot resist wondering if the concrete could/should have been kept smaller than the wood, so as to encourage the drip to fall away clean, not get trapped in the seam by capillary forces.

ps

Uncle Tony was my fathers brother who was better a giving advice than actually doing anything.

Absolutly impeccable workmanship throughout.

regards again

Marcus

Edited January 24, 2016 by difflock

[ucoulddoit]

Thanks for the compliment Corco 2000. I'm sure you could build this in some places without planning permission but there are local restrictions around here which was annoying. The slab is 100mm thick with a layer of A142 steel mesh. The location is not accessible from the road so I mixed the concrete in a Belle half bag mixer and cast it in three panels.

 

I used an MS391 which is on the small side for milling but it is for my own use rather than trying to make money so I just took my time. At the start of milling the timber for this project I already had an Alaskan Small Log Mill and bought an Alaskan Mini Mill to make it easier to cut the sides of the beams. About half way through milling all the beams, following advice from Alec (Agg221) I bought a 25" bar and a Granberg rip chain and also some extra bits for the mill so that I could convert it into an Alaskan 24" mill. The max bar length recommennded for the MS391 is 20", but as you lose 5 to 6" off the length once the mill is fitted I decided to try with a longer bar so that I could go up to almost 20" with the Alaskan 24 mill and this worked fine although a bit slow on a full width cut. Just starting to mill some more inaccessible larch logs this weekend into thick slabs which I'll be able to manhandle out of the wood and take to a bandsaw mill for milling into cladding to be fitted this summer.

 

 

Especially liked the tidy pads with (very long?)hold down threaded rod.

BUT!

the Uncle Tony in me cannot resist wondering if the concrete could/should have been kept smaller than the wood, so as to encourage the drip to fall away clean, not get trapped in the seam by capillary forces.

 

I cut the threaded rods (16mm dia) down a bit before fitting the posts. They are about 250mm long above the concrete and I cut a hole into one side of each post to fit a washer and nut. Worked a treat, much easier that I'd expected.

 

Once the timber cladding and a low blockwork dado wall is finished the posts/plinths will be sheltered from the rain but in the meantime water is wicking into the joint. There is a small chamfer around the top of the plinth and this could have been made larger for an exposed location. Also, it is difficult to cut the end of a post exactly square and finish the top of the concrete exactly level, so the post almost ineviteably sits on one corner or one side rather than over the whole area. To try to solve this, I put four layers of DPC material about half the size of column at the centre so that it sits on this and there is thin gap around the perimeter. But water is still wicking in so for an exposed location I'd think about a vertical steel plate in a slot and bolted through the column. But that is probably a bit over the top for a simple outbuilding.

 

Andrew

[arbwork]

Great job. Very impressed. There's a special feeling when you build something that you have taken from a tree to a finished product.

 

as above, interesting details of build and grading, looks good

[ucoulddoit]

I’ve just completed milling the larch cladding for this project using an Alaskan mill, a mini mill and a band mill, and thought the pictures below might be of interest to others who have freely available timber, but located at inaccessible places.

 

I used a few more of the larch logs which had been felled some years ago in the neighbour’s wood behind the house. They were further into the wood than those used for the frame, about 100 feet up a steep hill and although there is a narrow track a bit further up, it was just not possible to extract the round logs economically. As the cladding will be fairly narrow, 100mm wide vertical boards, I used the Alaskan and mini mills to cut 100mm thick slabs by 3.1m length from each log which could then be manhandled to the track from where I transported them to the sawmill which is less than 2 miles away. I cut off one side of each log using the mini mill so that the two or three slabs from each log could be placed together vertically on the bed of the Woodmiser, i.e. two or three slabs at a time were then milled into thin cladding boards, instead of one at a time.

 

The larch trees, some of which were 100+ years old, yielded some really good timber and much of the cladding is ‘boatskin quality’. The photos below give some idea of how inaccessible the trees were, the first cut revealing almost knot free timber, the stack of almost 2 tons of 100mm thick slabs, milling the slabs into thin planks and the cladding planks stacked for drying. About 75m2 total area which has worked out to be very economical, as it is for my own use.

 

I bought an MS661 after milling the first couple of small logs with my MS391 (which has more than paid for itself milling timber over the past few years), but with a bit of creative accounting, I’ve discounted the cost of that as I felt this was a large enough job to justify buying the bigger saw with a view to milling more in the longer term. It worked well having two saws, the larger one set up in the Alaskan and the smaller MS391 being used for cross cutting the logs and in the mini mill.

 

Andrew

[muttley9050]

Nice boards. The larch looks to be exceptional quality. Look forward to seeing the finished result. Will be starting milling for a green oak frame on Friday so looking forward to that too.

[timbernut]

Good work, I don't think the vertical plate n slot would be over doing it as it nice n simple.😀 Noticed you said larch had been down a while, so was wondering how long larch is usable for if left laying in the round in the wood (or a stack for that matter)?

[ucoulddoit]

Nice boards. The larch looks to be exceptional quality. Look forward to seeing the finished result. Will be starting milling for a green oak frame on Friday so looking forward to that too.

 

Planning to be finished by the Autumn but don't be surprised if it is later than that! Would be good to see some pictures of milling, fabrication and erection of your frame.

 

Andrew