Roof overhang limits

[imageel]

As @Fergie 307 mentions with a low pitch and given your latitude I'd be concerned about snow loading on the rare occasions we seem to see now in the UK.
WRT overhang my between the wars house has at lest 400mm pitched roof overhang and does not have any soffits so the rafters have exposed undersides but ends protected by the fascia. One advantage of having a large overhang is that falling rain is well clear of the walls and only wind will cause rainfall to dampen the lower part of the walls but never the upper metre or so.

 

[Mad Moose]

@Fergie 307 Good to know. Thanks. That is the very reason I came on here asking questions before I actually start.

As for snow load on the roof, I can't remember the last time we had more than an inch of snow here. Having lived in Canada for a while, however, I have witnessed real snow!

 

[Fergie 307]

One thing to bear in mind is your cladding. I have always used featherboards, so you can adjust the spacing to suit the height of the wall.
If you are planning to use any sort of jointed boards, shiplap etc, make sure you get the height of the walls to suit. Last thing you want is to start at the bottom then find you have a little gap at the top. Far better to dimension the walls so you have full boards all the way, or maybe have to trim a few mm off the top one. Nothing looks worse IMO than a run of full boards, then a bit an inch wide at the top.
With the pent shape it is obviously less of an issue, on the sides at any rate, but worth thinking about when you are planning.
Also may be beneficial if you buy as much as you can from the same source, they might well be prepared to give you some discount.
I have found my local independent builders merchant much better and generally cheaper than the big chains, and much more likely to be amenable to a bit of haggling.
The difference in prices between suppliers can be a real eye opener.

 

[Fergie 307]

I don't know how you are laying the slab. If DIY then a good tip I was shown years ago and I have used ever since.
Get a roll of DPC, the narrow type sold for brick walls. Once you have tamped and levelled the concrete get an assistant and pull the DPC tight over the shuttering at one end of the slab. Curl the leading edge up slightly like the front of a ski. Now pull it over the length of the slab, keeping it nice and tight. You may need to saw it slightly from side to side as you go. Gives a really smooth finish, almost as good as though it had been floated.

 

[flying haggis]

FWIW when I built my shed I had the roof slope to the front and overhang by about 300mm which gives a bit of rain protection to the door especially if you want the door open when working

 

[alex robinson]

Seems like you have a pretty solid plan already, but if you used structural insulated panels, you could have pretty much as big an overhang as you wanted. 80 cm should be fine, and you would get more headroom inside as the overall structure is thinner for a given amount of insulation.

Expensive, but they are magic!

 

[Mad Moose]

Seems like you have a pretty solid plan already, but if you used structural insulated panels, you could have pretty much as big an overhang as you wanted. 80 cm should be fine, and you would get more headroom inside as the overall structure is thinner for a given amount of insulation.

Expensive, but they are magic!

Thanks Alex. I did look at Sips but they cost was prohibitive. I have a budget for the build and as I see it, every £ not spent on the build is a £ I can spend on tools