Help needed...Pent roof design...Or any other suggestions?

[DabHand]

Hi guys.

A little about my project...

I'm building my first shed, I'm actually a mechanic but have always done joinery in my spare time as a hobby. So although what I make is usually made very well, I'm not clued up on all technical aspects or vocabulary, so bare with me!

Its a 18x8 building (originally a 16x7)
Concrete slab complete outer diameter(and middle) laid on dry and wet mix.
Base frame is 4x2 with 4x2 sill all the way round with 16" OC divided into 3 sections for ease of construction and doubling up joists.

I've actually used a shed that was already built (3x2) but have extended it using 6x4(2x3x2) on each panel join for extra rigidity and expansion.

Now I'm onto the roof.

It was originally a pent roof (pitch on the actual frame with basic flat roof frame joined on top). Obviously its too small to re-use now
but the main use of my shed will be for somewhere to store my tools, car parts and to do general work including wood and rebuilds, polishing, welding etc so I intend to keep it as a pent roof.

I had considered building an apex but the added head room won't be really needed and I intend to try and keep it simple and fit for purpose over form (thats the idea anyway)

The first problem I had was the shortest walls were too short for me, so what I had planned to do was use the extension timbers(I haven't cut the down to size yet whilst I'm still deciding) to also raise the height of the front and back walls (with the same difference of the original) so that my pitch would just be replicated and would just add a top plate.

But now I'm also wondering whether I should extend them all to the same height and just add the pitch onto the pent roof as a frame (if that makes sense)

So I'm wondering...

Should I put the pitch in the extended panels and do a flat roof frame construction (probably in 3 sections for the same reasons I did the base as I'm also building it on my own).
Should I have all the panels the same height and pitch the roof with a pent roofing frame.

Or

Should I pitch the shed panels and then just use joists with a birds mouth in the top plate and then finish off with a fascia board all the way around??

Sorry if my ideas arent clear, feel free to give me a suggestion(s) on how a professional, advanced woodworker would do this.

Thanks in advance, any help is appreciated.

Dave

 

[DabHand]

Don't all rush at once lol

 

[Tom K]

Hi Dave, do a few more posts and then post some pics. Think some of your terms are confused pent roof is " A " shaped to my knowledge.

 

[nev]

i thought a pent roof was a flat roof sloped in one direction?

 

[MMUK]

Hi Dave, do a few more posts and then post some pics. Think some of your terms are confused pent roof is " A " shaped to my knowledge.

No, a pent roof is a simple slope, and apex roof is "A" shaped.

 

[DabHand]

As above, pent roof is a sloped roof in one direction.

I'm just not sure whether to keep the pitch (slope) in my walls meaning they're cut at an angle to support a flat roof frame.
Have the walls all at the same height and pitch (slope) the roof (by building a triangular frame)

Just wondered if anybody had, you should do it like this, or I think this would be better because.

Thanks

 

[Tom K]

Hi Dave, do a few more posts and then post some pics. Think some of your terms are confused pent roof is " A " shaped to my knowledge.

Obviously confused myself thinking of pentagons (homer)

 

[fluffflinger]

Best bet by a mile is a Gambrel roof, practical and pretty too.

Will give you the height you seek without having to extend stuff and creates the most space above that can be converted into storage, of which you can't have enough. It's what I put on my little workshop and I've never regretted it.

 

[srp]

I see no one has answered your questions yet. Assuming you want to keep things as simple as possible, I would use the original tall side as your new short side. Knock up a new bit of studwork to sit on top of the original short side, big enough to make it the new height of the tall side. Put all four bits together on your base (the two ends will be the original height, but you can worry about that later when the roof timbers are on). I wouldn't worry about cutting birdsmouth joints unless the pitch is more than about 10deg, but you could use galvanised truss clips (Screwfix do them). Make up a couple more bits of studwork to fill the holes at the ends, slap some shuttering ply on the roof (much better and no more expensive than OSB).
Just from experience, put a polythene vapour barrier on the inside, and a breathable membrane on the outside before you put the cladding and roof covering on. And insulation in between the two. You need the vapour barrier on the floor as well. The simplest roof covering for this sort of roof is EPDM - very easy to lay and will last much longer than felt.

 

[nev]

as above. use your tall side as the new short side and extend the short side. If youre going to be working in the shed consider putting glass in the extension bit. simple to do, free glass from your local upvc place (old window scrap pile, make frame to fit) and more light to work in.

 

[MMUK]

If you're planning to put glass in the roof make sure it's toughened at least, if not laminated.

 

[nev]

If you're planning to put glass in the roof make sure it's toughened at least, if not laminated.

Maybe i should have explained better.
The suggestion was to put glass panels in the (top section) of the wall extension. very rough sketch below