Help: Posts sizes for an Oak framed garage

[Barreti]

Hi chaps,

Anyone bought an oak 'kit' garage who can advise me on the spec ?

I've finally got planning permission for a timber garage and gravel drive, which we initially asked the builder to do from scratch.
But we got looking at pre-manufactured oak kits and the builder is happy for us to buy in an oak kit rather than him sub it out to a joiner to do, and in fact the price for an oak kit is favourable compared to his softwood quote.

The kits come in 2 sizes - 150mm square posts and associated beams etc and 175mm posts etc.

But the builder said 150mm is nowhere near good enough to hold the roof we will be putting on it - concrete pantiles to match the house - and said we need 200mm x 200mm posts with 200mm x 50mm rafters.

The price for this is nearly double the 150mm kit price. The kit supplier says the builder is massively overkilling it and 175mm uprights in oak would hold up a block of flats.

To my mind, if the kit people say 175mm is that good then a good compromise is 175mm posts etc and 200x50 rafters.

Can anyone give me reassurance/advice?

This is a 6m x 6m 'carriage house' (ie it has no doors) and will be clad in 38mm oak.
I'm looking at the website for Rockingham Oak as they are relatively close.


Oh, I should add I did have an architect for this build and 6 months in he made absolutely no progress other than to get a structural engineer to the site who advised we needed 24 piles putting in. So we parted company, and we submitted a planning application based on a floating concrete base with no piles, which the builder is more than happy with. So its just us and the builder - and maybe an oak kit supplier.

Edited by Barreti on Wednesday 29th October 14:04

[Barreti]

For reference the price difference between the kits looks like this

150mm posts = £4600 +VAT (£5,520)
175mm posts = £5850 +VAT (£7,020)
200mm posts = £7360 +VAT (£8,832)

So the step up from 175mm to 200mm costs £1,800 to me, which is why I want to be sure I need to do it.

[Barreti]

Some brilliant answers chaps, and thanks.
And you know what they say about a picture being a thousand words. They're a great help too, because sitting at my desk today staring at the 6" mark on a ruler looked piddling. So thanks, they have helped visualise it in context.

The tiles on the house which we said we would match are concrete panties, though the builder said something about newer panties which are ok with the lower pitch roof on the garage kit of our choice.

[Barreti]

Well at the risk of stirring everything back up again, I thought I would update this thread as the oak frame started being erected yesterday.

3 x 175mm oak posts of the like I now have sitting on the mini wall would, in my opinion, hold up a jumbo jet!

The 6mtr posts are so heavy the builders can't actually lift them and have resorted to moving them around with the mini digger.

I'll post (excuse the pun) some photos if anyone is interested. I hope they have a few of the top beams up by the time I get home tonight.

Oh btw, I never saw the panties ipad clanger. Sorry about that and I'm glad it gave a few of you a laugh

[Barreti]

Here is the garage in its nearly finished state.

[Barreti]

How are you getting on with yours Jason61c - you must be well underway by now.

[Barreti]

Origin Unknown said:

Looks bloody lovely!

Might be further back in the thread but how are the sides and back finished?

The internal frame is visible, with panels made to fit into the gaps. The panels are clad in oak boarding.

We've learned a couple of lessons.
The supplier sent the 3 main oak sections too short- longest 6mtr pieces from back to front. That set us back about a month.
The stone plinths the front uprights stand on are covered in tanin from the oak. It might wash off, I havent tried yet. But the stonemason is a mate so I can get new ones if I need to. Getting the old ones out would be a sod of a job though.
The side oak-clad frames need pushing out a tad as water drips onto the bottom oak frame beam and then comes in. We could cure it with flashing but it will spoil the look so we will try moving things a little first.

I have to say my builder has been very good with ideas like chamfered bricks on the concrete pad and on the plinth for the frame.
He also made up soffits and facias with the spare oak cladding to stop the worst of the wind whistling through an otherwise open roof.

The drive is unfinished as it was originally planned to be gravel. But after having the path done I changed my mind and its now going to be block paved in black block to match the colour of the tarmac of the rest of the drive.

Maybe then I can get his mini digger out of the garage and use it !