Request for Comment - Garden Shed

[Tim Lamb]

Try Clarkes of Walsham. I bought some very nice real 4"x2" there recently. Invoiced as *paddock fencing rails pressure treated green 4.8m x47mm x100mm* £6.32/length.

+1. Go for brown pressure treated sawn from a 175 mm board. Gives 150mm cover. Don't use creosote. It'll make her eyes smart for weeks. If you intend to finish with Sadolin etc. paint the boards before fitting otherwise you will get stripes when they shrink. Chose which way round to fit the boards and stick to it. Harry says smooth (original board finish) side out; some theory about warping. I use the diagonal cut *out* as it gives a better rain drip and I prefer the rougher finish. The downside is that cobwebs stick like....

Tie beams have been covered by others but you might also consider stiffer timber for the door hanging posts and at least 4"x2" for the wall plate.

Ride on mowers are legal tender with our travellers so you might concrete in an anchor for a securing chain.

regards

>

[The Natural Philosopher]

One of its best features.

If you

yeah..

Nah/ If I go to 4x2 I have to go for that everywhere. Its only a shed..

THAT is a good idea

[jgh]

On the subject of roofs, can somebody with the appropriate knowledge update the Wiki entry on roof construction:

shows timber roofs with the attic floor joists running front-to- back so they form the trusses preventing spreading. All the houses I have experience of are terraced houses where the attic floor joists run side-to-side. What stops the spreading? Whenever I've been in the crawl space and in a position to look it just looks like the rafters are butt-nailed onto a wall plate on the top of the masonry wall.

Yes, there's the rafters holding the attic ceiling halway up the roof rafters, but instinctively they don't appear strong enough to do anything other than hold the ceiling up.

JGH

[Tim Lamb]

In message , [e-mail] writes

Exactly what I said to the builder who remodelled our house. The architect had used *raised tie* construction in a single storey wing butting up to an existing Victorian timber barn.

No loading was permitted on the barn wall and I said he should fit an additional tie at eaves level. The argument developed to the point where he claimed superior knowledge; having qualifications in structural engineering.

15 years later when he came back to quote on some alterations I was able to show that ridge had settled and the rafters had pushed out the supporting pillar making the garage door hard to close.

regards

[The Natural Philosopher]

well that can work up to a point. The narrowness of a terraced hose means the roof loading isn't as high and that reduces the lateral forces to the point where presumably the walls alone are heavy enough not to bulge or topple.

I am surprised though.It seems little gain and a high potential loss in doing it that way - you need the ceiling joists anyway - why not nail em to the rafters ?

Ah. You didn't mention THAT. Well in fact they only work in tension there so they have more than enough strength. Its resistance to bending and compression where wood is weakest.

If the rafters had infinite stiffness those alone would be enough to stop the spreading.

As it is the spreading forces will now be generated by rafter bending the triangular top bit is stable enough - so its the splaying of the 'feet' outwards that will be an issue.

I have that arrangement here, in the sense that my attic is storage only and the wall plate is a only meter above second floor level

the 'ceiling joists' are BOLTED to the rafters and they and the rafters and are substantial. But the structural engineers were happy enough.

[fred]

On Tuesday, August 14, 2012 12:52:10 PM UTC+1, The Natural Philosopher wrot= e:

I'd be inclined to put a bit of diagonal bracing in the roof at each end. J= ust a 45 degree lath running from the wall plate to the top of the truss. T= riangulation is your friend in this type of construction. It will help to r= elieve stress from wind force which is a main consideration in any roof. I'= ve built a couple of sheds with either wood or corrugated steel panel const= ruction and always like to brace both vertical and roof surfaces.

[The Natural Philosopher]

Mm. I expect there will be a fair bit of stuff left over at the end of the framing to add diagonals with.

The whole frame depends on the cladding for stability if I don't diagonal a wall or two. We had a 'wendy house', thing as a kid and we demolished it by removing the cladding and then we pushed..and the roof ended up on the ground ;-)

And I might want to diagonal across at ceiling level to to prevent parallelogramming. in the lateral plane.

Also pondering making the gable ends and the partition wall over one another on the ground and then hefting them up before infilling the front and back and roof.

In fact could do the whole thing that way apart from roof ..

[Phil L]

no need for rebar, and I've built masonry constructions on 100mm deep X

300mm wide concrete which are still standing 20 years on

Bolts set in mortar on one course of brick won't hold anything. Use threaded bar, bent at the bottom and set into the concrete strip footings, cut bricks where they meet the studs and then drill the bottom timber of your frame, bolt down then work off this

Weight of roof will bollocks these walls in short time. I'd be tempted to use 100X50's at each corner and every 1.5m in place of a

75x50

Opposing wallplates will need to be tied to each other to prevent spread from the roof, also some uprights from these to the ridge board.

'd be tempted to order trusses for these as they are extremely strong, come ready made and aren't much dearer than DIY.

[Tim Lamb]

Yes.

If you do clad last... the method I use...

As with any overlapping finish the first board needs a trim strip nailed up to bring the bottom edge out to match the rest. With a brick sub wall you will need to arrange this to coincide with the wall edge.

With the first board fitted I use a gauge (sheet steel 150mm x 75mm with a 10mm 90 deg. fold) to measure up and tap in nails every 2 or 3 uprights to support the next board. I use 4.2m lengths so this is essential when working from a ladder.

Stagger any joins. Nail up the next board and re-fix the gauge nails as you go....

regards

[fred]

Last shed I built I just poured the concrete slab. Made up the four sides. = Erected them and made them secure (bolted together and drilled and bolted t= o the concrete slab. Then erected the two gable trusses, ran the ridge boar= d between them and set and nailed the rafters. I tied the rafters about 300= mm down from the ridge after. Diagonal bracing in all four corners. Clad wi= th corrugated steel which was probably the strongest element in the whole l= ot.

But then it was only about 8ft x 12ft on plan.

I don't bother with windows but insert clear panels in the roof. More secur= e and if the scrotes can't see in it won't arouse there cupidity

[The Natural Philosopher]

sides. Erected them and made them secure (bolted together and drilled and bolted to the concrete slab. Then erected the two gable trusses, ran the ridge board between them and set and nailed the rafters. I tied the rafters about 300mm down from the ridge after. Diagonal bracing in all four corners. Clad with corrugated steel which was probably the strongest element in the whole lot.

Good points. What's the cost of slabbing versus using slabs? as it were..

[Fred]

I may get around to building a shed, so this thread has been very useful for me too.

Do you bend the threaded bar into an L shape? How big is the foot of the L: a couple of inches?

What diameter do you use: M8, M10, M12?

TIA

[Phil L]

whatever you can get hold of - it's only holding down timbers so it doesn't need to be anything major. You can bend it into an L shape or hook it like a tent peg, anything so that it won't spin when tightening the nuts

[fred]

On Tuesday, August 14, 2012 12:52:10 PM UTC+1, The Natural Philosopher wrot= e:

This might be useful though I think he is using massive timber sections. It= s interesting all the same