Shed help

[azk404]

Hello,

More carpentry then woodworking but I would like to build garden tools/bits shed in a little spot I have and wondered if my design was over kill at all, or if there was any suggestions to simplify it etc, or maybe this is good and I should go with this roughly ?

- Its roughly W 1680 x D 700 x H 2300/2000.
- Il make a base out of 4x4 and OSB to level it.

- The frame would be 4x2 (Or maybe 2x2 would be ok?
- Sides would be the 150x15 feather edge boards.
- Back is 11mm OSB, as this won't be seen.
- Roof would be 4x2 frame with 11mm OSB then some sort of felt as I have some left over.
- Doors are 22x150 as that seems to be the thinest treated I can find at local stores.
- 2x2 support for the middle front.

Any advice welcomed

 

[artie]

Looks like I'm first on the scene, so here goes.
Is it in a well sheltered spot, or will it be anchored? That tall and narrow could be blown over easily.
4 by 2 seems overkill, but no harm in that.
I personally don't like OSB floors but maybe ok in this instance since you'll likely just be reaching in.

How will you treat the OSB in the back? It will last a while outside but not long enough.

 

[Fitzroy]

I think you’d be ok with treated 63x38CLS for framing. It could feel a touch flimsy when just a frame but once you have the skin on it’ll be fine. As per Artie, OSB not great for long term exposure, it will delaminate and then the only option is to replace.

 

[Jameshow]

You could take the roof felt down the back and keep the back weatherproof?

3x2 CLS will be fine.

I think you need another couple of roof rafters to stop the OSB sagging.

And another stud in the side to stop the cladding moving too much and becoming gappy.

 

[azk404]

Yep its a pretty sheltered spot in an already roughly 12x12' fenced area and it will sit on concrete which I can anchor too. I was thinking of just using 4-6x L-brackets from the inside and screwing that to the base/ground before putting the floor OSB on. It also backs against a fence so I can screw into the post also for extra support.

I have some OSB left over so thought for the floor/roof it would be ok. As as you said I won't be stepping on it but if I did get something else what other cheapish options might you suggest?

Makes sense, il do 3x2s then, not sure why I didn't think of that

I was actually just going to paint the OSB with black Cuprinol fence paint as I had some left or should I seal with with something stronger first? Anything I can get at Builders Depot? - Builder Depot | Timber & Builders Merchants London | Building Supplies.

Potentially I could continue the felt, see how much I have first after doing the roof but could get lucky.

Cheers guys

 

[artie]

A quick mental calculation tells me you'll get floor and back out of two sheets of OSB so for economy that's the way to go.

What length felt rolls can you get?

Smallest in my local builders merchant is 10m, so more than enough to felt roof and back.

Couple of years ago there wasn't a big price difference between 11mm OSB and 12mm Malaysian ply, so I would have used it. But OSB has dropped <> 60% whereas Malaysian ply has only dropped <> 25%

 

[Jameshow]

Don't forget extra roof rafters otherwise within a year it will start sagging..

 

[mc281]

Extra rafters for sure.

 

[azk404]

Is it ok to line the OSB as the back so the seam is vertical. Its easier to cut it at the shop and fit it in my car that way ? How should I seal the joins and the OSB surface other than using felt?

I have to check how much felt but I think I have about 8m of 1m width left.

Copy on the extra rafters

 

[Jameshow]

Is it ok to line the OSB as the back so the seam is vertical. Its easier to cut it at the shop and fit it in my car that way ? How should I seal the joins and the OSB surface other than using felt?

I have to check how much felt but I think I have about 8m of 1m width left.

Copy on the extra rafters

Sure not a problem. Put stud behind it to hold it.

 

[azk404]

OK, work begins today, thanks for all the advice everyone

 

[TheUnicorn]

I may be missing something here but it looks like the tilt of the roof will channel all the rain down the back where it will be up against a fence and never dry out?

 

[Stanleymonkey]

Having just replaced an OSB shed roof - if it gets wet you will get all sorts growing on it once it's damp and it with just disintegrate pretty quickly.

 

[Jameshow]

Having just replaced an OSB shed roof - if it gets wet you will get all sorts growing on it once it's damp and it with just disintegrate pretty quickly.

Ply is much better imho for this application.

 

[azk404]

I might have enough malay hardwood ply I got to do some workshop cabinets as I stopped using it for the doors as that stuff smelt toxic when cutting and looked really s***

Would that be better? Maybe at least just for the floor as I have enough for that.

Was only using OSB as I had some but I think I’m going to cover it with felt as I should have enough to do the back at least.

Also the tilt will be positioned so it goes over the fence is it back against and there be about 100 mm between the shed back and fence also.

 

[azk404]

Forward tilt or back, I can’t decide !?

 

[artie]

Was it I, I would tilt forward, away from the fence, I would also leave a minimum 300mm gap between the shed and the fence.
A bit of air through there will work wonders. Especially if you use OSB

 

[ey_tony]

There's no such thing as overkill (well there is I suppose) with regard to sheds or other similar structures. Whatever you put into construction usually dictates how long the shed etc will last or how weather proof it remains.
For the extra cost involved I wouldn't use OSB. I built my double shed seven years ago on a raised platform with 18mm external grade ply for the floor. The same for the roof and it's still as dry as a bone. I used shingles for the roof instead of felt as the front half of the roof faces due south and it gets hot to say the least.

You don't have to go to the same extremes as I did but I'd certainly agree with the others with regard to leaving space between the rear and the fence to allow airflow.
Just noticed it looks like it could have been built by a Russian!

 

[artie]

I used shingles for the roof instead of felt

Just out of interest, what pitch is the roof you put shingles on?
I put them on a 15 deg roof one time and it didn't end well.

 

[ey_tony]

Just out of interest, what pitch is the roof you put shingles on?
I put them on a 15 deg roof one time and it didn't end well.

The shed roof is A-symmetric. There are two different pitches on the shed roof: one is 15 degs and the other is 20 degs. I also built a small covered storage section of the catio with a 15 deg pitch again on an 18mm ply roof and it too is very secure and dry.
If I might ask, why didn't it end well?

Myself, being a bit of a belt and braces type nut, on top of a liberal use of mastics for sealing edges, joints etc, as an added precaution I did put on a non-permeable membrane (link below) to the roof before fixing the shingles to both sets of roofs which were well secured to the 18mm roof material and they're just as secure and dry today as they were when they were put on 7-8 years ago.
I could have saved a bit of money by cladding the roof with 12mm ply but I chose 18mm instead as it flexes far less especially when fixing the shingles.
Temperature is also important when fixing shingles. The shed's shingles were fitted when outside temps were maybe 5-7 deg C which is essentially too cold so I used a calor gas torch to warm them before fixing.
Shingles take a fair bit of extra time and effort to lay when compared to regular roofing felt but aesthetically there is no comparison, they will outlast regular felt several times over plus I'm getting too old to be climbing up to replace roof felt if it cracks or gets ripped during storms.

Non-permeable membrane.
Protect A1 Roofing Underlay 15m x 1m - Screwfix