Garden Room/Shed/Man Cave help

[LearningCurve25]

Afternoon,

To all who are taking the time to read this and help me out, many thanks in advance! I've been researching a while on here and until recently had some help from a friend, but I need some expert advice so here goes.

Story so far...

I am just a DIYer and have built a garden room on a concrete base, the framing of the floor is 6x2 on 400 centres, insulated with Celtoex and the floor is 18mm WBP PLY. I've framed the walls in 4x2 and crowned them also, the roof is 6x2 on 400 centres with furrings added as I'm gonna run a flat roof which will be covered with rubber. The whole building has now been covered with a breathable membrane.

I'm now at the stage where I have bought the treated battening to clad and have a tonne of tongue and groove redwood sitting inside the room to dry out. I have a few questions for you guys.

Questions:

Screws or nails for fixing the 18mm WBP ply to the roof? Which length and size?

Is it ok the roof ply will be just fixed into the furrings and not joists or do I use long enough to do both?

When fixing the battening to the stud walls outside is it ok to use galvanised nails, if so which ones?

When fixing the tongue and groove to the battens, what is the best way? Battens are 20mm thick as is the cladding.

I'm thinking of hiring a paslode for the cladding with 63mm straight Brad nails (cladding is 20mm thick and so are the battens) but am unsure if this is ok and if I need stainless steel or galvanised? Do I leave a gap for expansion and if so, how much?

Which treatment will be best for the type of wood I'm using? As with everyone I really want this to last as long a season possible so what would be the future care?

Looking back over it, it's a lot of information that I need so to anyone who takes the time, thank you so much.

Thanks again!!

 

[LearningCurve25]

Anyone?

 

[r896neo]

Furrings are often glued and nailed. You should screw your ply down with 4.5mm x 60mm or bigger.

For treatment you want a good quality UV shielded product, if going for clear it needs to be solvent based rather than shed type treatment. Sikkens or sadolin etc.

Expansion will depend on the timber and how its been stored. The end grain is the main issue as it may swell a fraction so up under soffits its hidden but your main issue will be around window/ door reveals. 3-5mm is probably about right. I assume the cladding is going vertically?

For nails you really should use stainless steel if using a clear treatment. If you are painting a colour then go for galvanised as they are much cheaper. You want galvanised ring shanks and I have found the galvanising to be best on the paslode branded ones marked as galv+ If you are within a km of the sea definately use stainless.

No point putting 23mm of nail into thin air so just use 40mm.

For fixing the battens use anything, cheap galvanised ring shanks are fine but use 63mm.

 

[LearningCurve25]

Thanks neo.

Originally I was buying Cedar and was going to double batten and run vertically but it came in at around £2500 so I've ditched that idea in favour of running redwood and running it horizontally. I've bought lengthens in 4.8+, is it ok to run these as a total length (e.g. No cuts) or should I be cutting and fixing? Probably a weird question as it's more work but thought I would ask.

Some of the timber cladding is wet and some dry, I'm going to treat it before I nail it on, I was thinking of using a paslode gun to fix it with galvanised nails and paint treat it. Would I be correct to treat the cladding at edges and front and back or just edges and front?

Could I treat with clear sadolin and then use another treatment to paint?

Will definitely take your advice on board and use it. Thanks so much for taking the time to reply, it will really make a differences.

Cheers!

 

[r896neo]

Full lengths are fine.

I would treat all cladding on all sides with Larsen clear timber preservative and then treat ends and outer face with a colour if you wish. I use cuprinol trade opaque cladding stain and quite like it.

You must let the wet timber dry out before putting it up as it could shrink a bit making your 3mm expansion gap look like a huge uneven 7mm.

I assume the cladding is not pressure treated?

 

[LearningCurve25]

Here I see a link to what I have bought:

http://www.championtimber.com/Timber/Claddings/25-x-125mm-nom-treated-redwood-joinery-tgv-dual-sided

Can I treat it all whether it's wet or dry or does it all have to be dried out before I treat it all?

I'm assuming it will take a while to dry, especially if it's still stacked. I guess I will have to separate it all out and get it in the sun??

Thanks.

 

[LearningCurve25]

The garden room is L4.8 x W3.2 x H2.4

I've found these:

http://www.diyandhardware.com/larsen-wood-preservative-green-5litre

https://www.tradepaintdirect.co.uk/cuprinol-trade-cladding-and-fence-opaque-finish.html

Just wondered how many of each I would need?!

Invaluable information. Thanks again!!

 

[r896neo]

You want that larsen stuff but it also comes in clear. Other mftrs cuprinl, ronseal etc do the same product. It very thin so quickly soaks in. It can even be sprayed. Its cheap so it only comes in 5 ltrs.

It doesn't need to dry thoroughly just let excess drain out. Timber stored outdoors can have a significant moisture change once its up and that can shrink leaving your gaps uneven.

As for the colour hard to know. Follow advice on the can, you'd certainly need a 5ltr can I imagine.

 

[LearningCurve25]

Ok, thanks again. One last question I guess.

I have it stored outside but inside the garden room itself, if I leave it to dry out (as best as I can) and then apply the preservatives/protection what sort of a gap should I leave between each board?

If there's any other information anyone can add, please do so!

 

[LearningCurve25]

I have bought the Larsen stuff so I'm gonna treat the wood both sides with that first.

I want to paint over it to colour the wood but I want to protect it as much as I can also. What is the best exterior wood paint for the wood I am using? (See link below)

http://www.championtimber.com/Timber/Claddings/25-x-125mm-nom-treated-redwood-joinery-tgv-dual-sided

Thanks in advance!