Workshop\Shed Construction

[DaveL]

WiZeR,

That is a weak point but cutting the notch so you remove a minimum amount of timber should be ok, I think you picture shows a deeper cut than is needed or use a metal hanger so the load is on the bottom edge of the rafter.

 

[mahking51]

Wizer
Just finishing off a similar shed but not a lean to type.
Important thing IMHO is to go for a fibreglass flat roof, spend a little more at the start then forget it for 20+ years!
Mine is 1/2" shuttering ply trimmed flush all round then covered with bonder then a layer of 600gsm chopped strand mat and finally a heavy topcoat of waxed gelcot. Edges are prefromed GRP roofing channel; front is preformed GRP dip channel and rear is drip channel into guttering. Comes in any colour (olive green) and will look great.
Over the years I have totally had it with roofing felt and corugated materials.
Will post some pics beforethe roof goes on.
Regards
Martin

 

[mahking51]

Here are some pics of the shed; roof goes on tomorrow!

Here are two details of rafter setup, note small wedges to avoid having to cut rafters; there will be a fillet of 1/4" marine ply between rafters to bring up to level for roof boards.

Interior is filled with 25mm poly insulation covered by shuttering ply; windows are to be opaque security glass with wire inside.

Regards
Martin

 

[wizer]

ooo lots of questions Martin!

Shiplap on the outside?

What is the black material between the wall and shuttering ply?

Are you running electric into the shed? If so how do you get the wires around the poly insulation?

what are the dims? Mainly the height front and back?

What are the dims of the timber? 2x4? or 2x6?

Was there any reason you used planed timber?

I'm not sure I really understand what your doing with the rafters? What are the dims of the fillet pieces and why did you not use timber of the same dims as the rafters?

I also note that you have the rafters laying flat as apposed to on their side. For some reason I hadnt considered this, I guess this makes sense and will add strength to the roof.

I'd like to see a picture of the finished roof as it's hard tp picture from you explanation. "bonder then a layer of 600gsm chopped strand mat and finally a heavy topcoat of waxed gelcot" not sure what any of that is lol

The main reason i'm considering the twinwall roof is for light. There will be only one window at the back end of the shed in the door. The other alternative is to put in a couple of 'Bubbles' or Roof Windows.

Thanks for posting your pics, it helps to see something like this in progress.

 

[dedee]

Wizer,
Have you considered corrugated bitumen roofing sheets, Onduline ? http://www.slecladding.co.uk/ondul.htm

I've seen it used extensively in France and have used the lighter Corroline on a shed here. Opening rooflight windows are available and although this is not from experience I reckon this would last longer than the plastic variants that must become brittle and discolour over time.

It is certainly very easy and clean to install.

Corroline is available from Wickes, Homebase etc but I guess the windows would have to be ordered.

Andy

 

[wizer]

that's it Andy, go and throw another one in there to confuse things!

Looks good actually, i'll have to see how pricey it is

 

[mahking51]

Wizer,
Shiplap outside is 16x125mm treated, 67p +VAT per m from Blamphayne Timber in Devon, 9.5m run per square meter of area.

Black Material is standard semi permeable roofing membranwe stapled over the studding; shiplap goes over this on the outside; layer of 25mm poly on inside then inner lining of shuttering ply.

No electrics in shed, it is going to be just for storage with timber racks and old kitchen cupboards to keep all the stored crap out of my workshop!

Shed is 19 feet long by 6.5 feet wide; 6 foot 6" at front; 6 foot at back.

Framing timbers are nominal 4x2 (89x38mm) CLS treated timber for base mounting and nominal 3x2 (63x38mm) CLS for studding; 4x2 CLS for rafters. CLS is cheaper than normal sawn 4x2; 3x2 etc and much nicer to work with. I allowed about 5% over for warpage etc which was about right.

The 1/4" fillet pieces are only for the front edge to take up the slope (5 deg) of the roof rafters so that the ply boards sit flat. They are just strips of scrap ply.

4x2 rafters are falt to give more fixing width to roof boards and also to keep overall height down.

Have now got windows in and roof on and glassed but have to wait until Monday early morning to put on top flowcoat as it was way too hot to apply after the glassing, would never have cured properly.

Have had to abandon safety glass as it was £42 a pane, silly money so have gone for ordinary float and will spray opaque on inside.

Will post some more pics later.

Regards
Martin

 

[wizer]

thanks for the info Martin, has helped with my plans a lot.

 

[wizer]

right, i'm moving on with my design now. I have slightly adjusted that rafter joint to make it more meaty.

I'm putting the roof detail on the back burner for a bit while I research all the options.

The front is going to have a rolling garage door. I need to find some technical drawings on these to find out how I design the front end of the shed.

On the back of the shed I want double doors across the full width. To maximise on light I want them to have large glass panels in. Could anyone suggest a method of constructing the doors? I have mocked up just a frame to illustrate where the doors are going. Can the doors be made in much the same way as the wall frames? I'm thinking about cladding the back of the shed with something nice like Cedar or Oak, so would like to build this into the design of the doors.

Current Sketchup File

 

[mahking51]

Wizer,
My first thought is that if you are having a roll up door the top lintel needs to be quite substantial, more than just a 4x2.
Also I believe that you need some head space above the lintel for the door to roll into which is lacking with a lean-to design because of the slope of the roof in the end frame.

I have added two or three small vertical noggins between the horizontal lintel and the sloping rafter for strength.

Regards
Martin

 

[wizer]

thanks martin, I had considered the headspace problem and then just decided to ignore it in the hope that it'd go away! :roll: I need to find a product and then find out measurements. I guess a little over hang wouldn't be too much of a problem. hmmm maybe an up-and-over door, but personally i hate them.

I had also considered the noggins between the horizontal lintel and the sloping rafter, but I was too lazy to draw them!

 

[mahking51]

Wizer,
You might consider having two conventional doors but with one of them working in 'fixed' mode whereby for most of the time it is locked shut forming an end return wall with the 'real, normal' door closing to it.
Then if occasion demands, it can be easily opened wide for better access.
I would have done this but was restrictd for total width.
Regards
martin

 

[wizer]

ahh if only Martin. The front of the shed slopes up quite steeply. So the doors would have to open in. Not ideal.

But I like your idea for the back doors and am going to adjust it so one door is smaller than the other.

 

[wizer]

Hi guys, we're getting close to the start of construction now! I'm like a kid waiting for xmas!

I need to think about cladding. One wall is going to be fixed to the house, the other will be just 15cms away from the fence and so will not be seen. How do you think I should finish this wall? Just board and felt? or shall I use weather board?

Also the front and back will need cladding. As this is the front of the house and the back looks onto the garden AND its a relatively small area, I was thinking of cladding it with something 'nice'. But not sure what? Shiplap? Hardwood? Something else?

Would appreciate your views.

 

[WellsWood]

So you're going indoors finally then? :wink: Like your design Wizer, I wish I could find the time to learn SU. Hmm...think of all those "winter" projects you'll be able to do.

OK, I might as well stick my twopennyworth in. A few thoughts in no particular order:

1. I would definitely bolt the wall plate to the side of the house and use joist hangers. I have used this method a few times now on similar projects and they're all still standing. It will add considerably to the stability to have the whole thing attached firmly to the house.

2. If you're going to use any kind of corrugated clear roofing you need to be aware that it will be very noisy when it rains. It also has very poor thermal properties: it stands a good chance of being a greenhouse in summer, and a fridge in winter.

3. I agree with Martin, Roller doors are heavy and I'm not convinced your structure is up to the job. He's also right about the fairly large space over the door to roll up into - have you got the headroom? What about one of those segmented up'n'over GRP things? - might be more suitable (and probably a lot cheaper).

4. You will need to make sure that the entire stucture, including any guttering, is on your side of the boundary. Otherwise it is feasable, no matter what your current neighbour says, that should the house next door change hands the new owners could make you remove the offending bits. A hassle best avoided at the outset, I believe.

5. Have you thought about security? If you're going to fill it with tools, and considering it appears to be visible from the road, you might want to be very careful about working with the door open on that side. It only takes one wrong'un to wander by and see in for you to get a late night visit. With this in mind my thoughts would be that a more substantial roof made of ply would be more suitable. You could always fit rooflights and if they were the opening kind you'd get some ventilation back to make up for having the door closed. It makes little sense (to me) security wise to fit nice strong doors and locks to something with a roof that can be opened with a penknife.

Good luck with your build anyway, give me a shout if you need a hand, I'm only down the road.

Mark

p.s. Martin, I hate to be a wet blanket, but I think you'll live to regret putting your rafters "flat". Even a relatively short length of 4x2 will sag over time just under it's own weight when laid like that, and from your pics it looks like CLS - about 38mm thick? - unlikely to take your weight while you're up there putting the roof on. Falling even a few feet onto concrete can hurt - a lot!

 

[wizer]

So you're going indoors finally then? :wink: Like your design Wizer, I wish I could find the time to learn SU. Hmm...think of all those "winter" projects you'll be able to do.

thanks for your comments Mark. It will be great to come in from the cold.

1. I would definitely bolt the wall plate to the side of the house and use joist hangers. I have used this method a few times now on similar projects and they're all still standing. It will add considerably to the stability to have the whole thing attached firmly to the house.

Cheers, the wall will be bolted to the house

2. If you're going to use any kind of corrugated clear roofing you need to be aware that it will be very noisy when it rains. It also has very poor thermal properties: it stands a good chance of being a greenhouse in summer, and a fridge in winter.

Should have updated this thread on that. I have infact decided to go with a solid sheet roof with maybe some rooflights or a dome. The main reason for this was the cost.

3. I agree with Martin, Roller doors are heavy and I'm not convinced your structure is up to the job. He's also right about the fairly large space over the door to roll up into - have you got the headroom? What about one of those segmented up'n'over GRP things? - might be more suitable (and probably a lot cheaper).

I have spoke to the manufacturers of the rolling door and they seem to think it will be ok. The design incorporates the right amount of headroom for this.

4. You will need to make sure that the entire stucture, including any guttering, is on your side of the boundary. Otherwise it is feasable, no matter what your current neighbour says, that should the house next door change hands the new owners could make you remove the offending bits. A hassle best avoided at the outset, I believe.

Yep, the whole thing is within my boundaries.

5. Have you thought about security? If you're going to fill it with tools, and considering it appears to be visible from the road, you might want to be very careful about working with the door open on that side. It only takes one wrong'un to wander by and see in for you to get a late night visit. With this in mind my thoughts would be that a more substantial roof made of ply would be more suitable. You could always fit rooflights and if they were the opening kind you'd get some ventilation back to make up for having the door closed. It makes little sense (to me) security wise to fit nice strong doors and locks to something with a roof that can be opened with a penknife.

I have not yet thought thouroughly about security. The roller door at the front will remain closed at most times and will probably have cabinets infront which will be on casters. I need to think about how the back doors (built by me) will lock securely. The windows in the doors will not be openable. The rooflights, if used, will need to be secured in someway. The workshop will also have an independant alarm system.

 

[WellsWood]

I have infact decided to go with a solid sheet roof with maybe some rooflights or a dome. The main reason for this was the cost.

If you mean boarded and felted I know a great chap up in Thamesmead for roofing supplies. Cheap, friendly, and full of good advice, he also delivers the stuff to your door. Gave me the confidence to re-roof my own workshop last year - saved me a bundle.

Looks like you're all sorted then, I'd get stuck in if I were you before this good weather disappears!

Mark

 

[wizer]

sounds good Mark

What would I need? Just ply and felt? Not looked into this yet

 

[WellsWood]

I used these instructions. It's for flat roofs, but the principle is the same. Just a matter of getting the high bits overlapping the low bits - an oversimplification I know, but not rocket science by any stretch. With the money saved over twin/triple wall clear roofing you could fork out for a couple of nice velux or similar roof lights. Board the underside of the rafters (I think there's a white ceiling board you could use for this) and infill with rockwool - hey presto, bright, airey, and cosy.

Mark

 

[OLD]

Cladding i used this product its cement fibre so no maintenance a 3.6 m length was £6 + del. so less expensive than cedar might be good up against the fence etc if you click my www button you can see how it looks on a smaller building