Dom's workshop build

[DomD]

Looking at roof and wall structure now:
For the roof I will have the breather membrane draped over the rafters and hanging over the end of the building enough to run into a gutter. Then will be battens at 1000mm centers and a metal box sheet roof.

The walls I am planning to use a breather membrane, battens at 500mm centers and then the feather edge. Corners will be this:

not as elegant as Mike's solution but quicker and requires no rip cuts.

A few questions:
Is there any way to cover the breather membrane from below the rafter tails (so when you look up you see something other than just a membrane)?
How is the void between the roof battens ventilated?
How is the gap behind the top of the featheredge in the 'How to build a shed' diagram created with this eaves detail?

Thanks, Dom

 

[MikeG.]

Waaaaaaay too many nails. You'll knacker the timber.

 

[DomD]

Ah right.. what should I be using then? They are just schedules I have found online. I could cut down to two each?

 

[DomD]

Gable roof almost done - couldn't do final four sets of rafters as my last jigsaw blade, used to cut the notches for lookouts, broke.
Also added some of the eaves closers.

 

[DomD]

I was test fitting the sheathing today and have found a problem where it overlaps onto the blocks. Because of bowed timbers and slight misplacement the osb is unable to lie flat on across the overlap.
I see too potential ways to go around this:
I could just nail the sheathing on down over the blocks or I could cut the sheathing so it does not go below the timber frame; I would then need to find something to cover the blocks later.

 

[DomD]

Gable ends done; I added a 2x4 above the ends as a point to attach the sheathing.

Still unsure how I will solve the above issue if anyone has any ideas. Perhaps I could add some osb spacers between the sheathing and frames?

Dom

 

[DomD]

Another question: do I need threaded rod through the ties even though they lie on the top plate? Thanks

 

[MikeG.]

Four nails equals a bolt, I think. So two or three nails from the tie into each rafter end, and one or two into the plate, and you then don't need a bolt. Personally, I wouldn't nail so often, and I'd bolt, say, every third tie.

 

[DomD]

I've already nailed enough then so won't put them in.

Lots of progress - installed both gable ladders, planed down all eaves closers and have begun sheathing the inside with osb.

The more time I spend on this the more I want to put something nice on the roof. I was having a look at clay tiles (used lots in our area) and may use them instead of a sheet.

I also am regretting not planning to put roof windows in - I know they are an extra expense but would provide far more light than the large window.
Would cutting through a rafter and adding double 2x6 'lintels' above and below the window opening be a possibility? The velux ones seem fairly straightforward to install.

Thanks

 

[MikeG.]

If you are planning on using tiles, then cutting a rafter and trimming an opening is only do-able if you double-up the adjacent rafters.

 

[DomD]

If you are planning on using tiles, then cutting a rafter and trimming an opening is only do-able if you double-up the adjacent rafters.

If I were to install a proper (e.g. velux) roof window on an onduline roof (I checked and this is supported) would the extra rafters be required?

I have sheathed a gable end wall. The tops and bottoms are not nailed as they have nothing to nail onto; I assume that's not a problem as gable end walls are non structural?

Thanks

 

[MikeG.]

Put something on the plate (scraps of batten off-cuts, for instance) so that you can get some nails in along the free edge of that sheathing. You don't want flapping bits of OSB, as it can soon take on a shape of its own.

If you have an Onduline/ Coroline type roof then you probably don't need to double up the rafters around a trimmed opening......but check first that Velux have a suitable flashing kit for that type of roofing. You wouldn't want to end up with a hole you couldn't fill.

 

[DomD]

Put something on the plate (scraps of batten off-cuts, for instance) so that you can get some nails in along the free edge of that sheathing. You don't want flapping bits of OSB, as it can soon take on a shape of its own.

If you have an Onduline/ Coroline type roof then you probably don't need to double up the rafters around a trimmed opening......but check first that Velux have a suitable flashing kit for that type of roofing. You wouldn't want to end up with a hole you couldn't fill.

Ok, will do that with the battens

Velux have a section in their guide for profiled sheets and have confirmed it works with coroline, I will just need to add a sheet overlap at the right place.

 

[DomD]

All walls boarded and a window routed out, just need to finish the gable, then on to the roof.

 

[DomD]

Final gable end boarded:

Then I went onto the roof window opening, dark photo unfortunately:

There are certain places (e.g. under the lookouts) that 100mm insulation won't fit, should I just be filling this with expanding foam?

Finally, should the roof be boarded with osb horizontally or vertically?
Thanks

 

[MikeG.]

OSB: whichever way suits. And yes, if you can't get 100mm of insulation in, then get in what you can. With solid stuff either side, expanding foam is fine and a useful weapon in your armoury.

 

[DomD]

Ok, I have a gun so should be easy enough to apply.

Did the lower parts of the roof today:

There are definitely gaps e.g. between boards and around the cutouts but hopefully not large enough to compromise the vapour barrier.

Do I just leave these sheets flying top and bottom? I will add an off-cut for the edge on the unsupported side of the cutout.

I then put one upper board up which took two people and lots of work

- others won't go up until Saturday as I am out of osb; hopefully wall insulation and membrane tommorow.

Dom

 

[John15]

I'm enjoying your workshop build Dom. It's making my workshop look pretty shoddy!

John

 

[DomD]

I'm enjoying your workshop build Dom. It's making my workshop look pretty shoddy!

John

Glad you're enjoying it, I'm avoiding taking photos of all the minor mistakes!

I've got the drip edge in now, onto cutting insulation.

 

[DomD]

Door detail:

Corner detail:

Unconvinced about these but that seems the best I can get - should I fill any potential ingress points with silicone?