Garden room / posh shed /workshop build log

[Deleted User 298457]

isnt there going to be irregularities in the roof now were those upside down joist hangers sit. surely the osb wont sit flat due to the metal and nails standing proud of the joists.

Building a garden room not a swiss watch.

 

[Buffman]

isnt there going to be irregularities in the roof now were those upside down joist hangers sit. surely the osb wont sit flat due to the metal and nails standing proud of the joists.

It'll be about 1mm. There's 37.5mm of fall per m so should be fine. Flat rubber roofs can hold /pond water anyways.

Given it's rough Sawn timber it's probably got more than 1mm of deviation across the circa 4m span

 

[Buffman]

Got my doors and windows.

Got to do a bit of googling to do on how to fit them! Paranoid they're going to break also.

Did you back calculate how far forward to put them so the corner pieces of the cladding work with it @dlockers? (Ie save cutting)

Also @dlockers do you know if it still needs cross braces until the roof OSB is on or is it fine once the roof is tied? Feels damn solid now.

 

[Deleted User 298457]

I redid the heal and toe on one of my bifold today and got some more noggins in! Sick of PIR now lol. I need to swap my 13cm coach bolts for 10.

I put the doors as far forward as I could as the cladding etc will easily eat them up. No precise maths.

All bracing can come off now, it's basically done once the roof and walls are osb'ed.

 

[Buffman]

I redid the heal and toe on one of my bifold today and got some more noggins in! Sick of PIR now lol. I need to swap my 13cm coach bolts for 10.

I put the doors as far forward as I could as the cladding etc will easily eat them up. No precise maths.

All bracing can come off now, it's basically done once the roof and walls are osb'ed.

Ah cool.

For the bracing I haven't yet fitted all my roof OSB so do I need to wait? Was going to fit my doors /windows tomorrow before the rest of roof as the weather isn't great

 

[Deleted User 298457]

Meh, should be fine.

 

[danlightbulb]

How come you've doubled up all the roof beams? What size are they?

 

[Buffman]

How come you've doubled up all the roof beams? What size are they?

5" by 2". If you double them up it increases the carrying capacity by circa 15% apparently. They try keep the sizes low so that the height is where it is you want it (ie internally)

 

[WillyNelson]

Sick of PIR now lol.

I feel that. It's such horrible stuff to cut. Just ordered another 3 sheets of 100mm to insulate the roof.

I've just been using a normal hand saw to cut them and the amount of 'snow' it makes is unreal and awful to have blowing about the garden. Kind of need a long thin knife to do the job instead.

 

[Mercenary Keyboard Warrior]

I feel that. It's such horrible stuff to cut. Just ordered another 3 sheets of 100mm to insulate the roof.

I've just been using a normal hand saw to cut them and the amount of 'snow' it makes is unreal and awful to have blowing about the garden. Kind of need a long thin knife to do the job instead.

Bread knife

 

[LuckyBenski]

Bread knife

Been saving an old one for exactly this purpose!

 

[Deleted User 298457]

Panel is definitely easiest... I must have done over 150sqm of it now. Tried everything - always come back to a nice blunt-ish panel saw.

 

[Buffman]

I didnt find cutting the PIR that much of a pain to cut.

Ive now got some windows in and I'll ashamedly admit it took 2 days! Hoping to finish the roof tomorrow

 

[Deleted User 298457]

Looks mega. Good to see the interior is fully furnished and how it'll likely look when its "done done" too

 

[WillyNelson]

Bread knife

Excellent shout. Might have to buy a cheapo one next time I’m in Sainsbury’s.

Next conundrum is solving that fine line between cutting the PIR sections slightly too small so they don’t hold between the ceiling joists, and slightly too large that I have to wallop them in with a woodblock and mallet!

 

[Deleted User 298457]

Excellent shout. Might have to buy a cheapo one next time I’m in Sainsbury’s.

Next conundrum is solving that fine line between cutting the PIR sections slightly too small so they don’t hold between the ceiling joists, and slightly too large that I have to wallop them in with a woodblock and mallet!

If the roof is at 400 gap then tbh the rounding error during cutting generally gives you a nice halfway house. I did my entire roof today pretty painlessly - only 2 or 3 out of 30+ that gave me a headache. Cutting a 2.4m sheet into 400mm blocks means you always end up some tight/some lose, but generally you get away with it every time.

 

[Buffman]

Roof OSB is on just needs trimming

 

[WillyNelson]

If the roof is at 400 gap then tbh the rounding error during cutting generally gives you a nice halfway house. I did my entire roof today pretty painlessly - only 2 or 3 out of 30+ that gave me a headache. Cutting a 2.4m sheet into 400mm blocks means you always end up some tight/some lose, but generally you get away with it every time.

You’re obviously more accurate with a saw/breadknife than me

 

[Deleted User 298457]

You’re obviously more accurate with a saw/breadknife than me

Panel saw - it's quite hard to go wrong if you use the full length of the blade. You can always make a jig out of some CLS too

 

[Matt-Page]

For cutting PIR I used a jigsaw with a bradknife serrated type blade. Made a nice tidy job of it without hardly any tearing or dust from it.

To get PIR to fit nicely, you can use Gapotape. You only have to get the cuts sort of accurate, then the memory foam compresses. Also improves the vapour barrier. It is however and additional cost and takes more time...