Horizontal cladding on garden room

[Wils81]

Looking at either shadow gap or shiplap timber cladding for my garden room. I've fit vertical battens. The length of the room is nearly 6m. If I get smaller lengths (3.6/4.8etc),what is the best way to create the seam, is it just a case of staggering the joints vertically or should I use some kind of trim to hide a straight line seam.. TiA

 

[JohnD]

I think you have to accept that a bit of damp will get behind the cladding when it rains, and will dry off in the sun. Treat the ends of the boards with wood preserver and stain before fixing, you will never reach it afterwards. I'd stagger them alternately. A cover strip will hold damp.

You can put breathable membrane behind the battens, but there should not be much damp. In summer the gap between the boards will open up, exposing any untreated timber.

I found it easy to treat all the boards and battens, all surfaces, and drill the screw holes, before fitting. It also does a better job. You need small stainless screws or you will get stain. I used teak strip to cover the ends, I live in a boat building area and got some scrap. I expect treated timber will do.

The bottom boards will fail first, damp from rainsplash. Make a few extra so you can screw them on when the originals need replacing. Try to have them overhanging, not touching, the dwarf wall or whatever is beneath,

 

[freddiemercurystwin]

With a breather membrane, vertical battens and then cladding that should provide a good rain barrier with no damp ingress. As for the gaps between the ends of the boards fit an epdm tape to the front of all battens, then it will be black if visible. The epdm tape is considered good practice nowadays for all cladding of this nature as it provides additional protection to the battens as well as hiding the face of the battens.

 

[Wils81]

I think you have to accept that a bit of damp will get behind the cladding when it rains, and will dry off in the sun. Treat the ends of the boards with wood preserver and stain before fixing, you will never reach it afterwards. I'd stagger them alternately. A cover strip will hold damp.

You can put breathable membrane behind the battens, but there should not be much damp. In summer the gap between the boards will open up, exposing any untreated timber.

I found it easy to treat all the boards and battens, all surfaces, and drill the screw holes, before fitting. It also does a better job. You need small stainless screws or you will get stain. I used teak strip to cover the ends, I live in a boat building area and got some scrap. I expect treated timber will do.

The bottom boards will fail first, damp from rainsplash. Make a few extra so you can screw them on when the originals need replacing. Try to have them overhanging, not touching, the dwarf wall or whatever is beneath,

When you say teak strips, was that L shaped for the external corners

 

[Wils81]

With a breather membrane, vertical battens and then cladding that should provide a good rain barrier with no damp ingress. As for the gaps between the ends of the boards fit an epdm tape to the front of all battens, then it will be black if visible. The epdm tape is considered good practice nowadays for all cladding of this nature as it provides additional protection to the battens as well as hiding the face of the battens.

Would you stagger the boards randomly?

 

[Wils81]

Now wondering if tongue and groove vertically would look neater

 

[freddiemercurystwin]

I think staggering looks vastly better, as for T&G or not it's up to you what you like the look of/can afford. If it were me I'd be using cement cladding rather than timber, Marley weatherboard or similar though last time I checked Hardie Planks from James Hardie were the cheapest.

 

[JohnD]

When you say teak strips, was that L shaped for the external corners

No, just 2x1 inch. I butted it to the ends.

Planed but rounded corners. Must have been left over from something in the boatyard.

 

[JohnD]

Now wondering if tongue and groove vertically would look neater

I've had vertical T&G, and every board rotted at the bottom, where rain soaked into the end grain, both running down the boards and splashing up..

Hence my replacement with horizontal shiplap.

The horizontal are less prone, but I drenched the bottom two with wood preserver, and made some spares which I tucked behind the cladding. I can unscrew any rotted ones with ease

 

[JohnD]

If I was doing it again, I think I would add foam slabs behind the cladding, for thermal insulation.

 

[big-all]

Overhanging roof by around 150mm on edges with gutter on the bottom off the roof slope
on my 12x10ft no joints on the 5"[110 coverage] txg shiplap
20 years on around 2 coats off ducks back every 2-5 years 20 years old this year as good as new but needs re-coating as 6 years since last coat
just get the ends close together flood with ducksback and it will form a waxy skin to shed the water
ducks back is a 100% surface waxy coat so no water penetration at all
you can go the in line route rather than staggered joints with cladding but will use more timber as you will have far more offcuts that wont fit in

 

[big-all]

and you must 100% always have outer cladding air gap breathable membrane then insulation ---and i mean 100% off the time
having said that i got my cladding pressure treated and overdone the ducksback 2-3 coats every 2 years so about a coat on average say 12-15 months for 14 years so 9-10 coats then nowt for 6 years i dont have an air gap breathable membrane or ventilation and used loft insulation and no damp at all but my setup relies on 100% non penetration where in life you must allow for leakage as most setups will have normal /reduced or no maintenance so need to cope with the inevitable moisture ingress [leak]

 

[Wils81]

Yeah I've got 300mm overlap at front, 200 at back and 170 at sides, roof is flat but dual sloped due to size of build and keeping roof joists down in size. Tyvek wrapped and 2x1 battens for airflow. Bottoms rotting if running vertical worries me, so back to horizontal. Was trying to keep costs down but may just bite the bullet and get spruce or siberian larch. I'm actually a decorator by trade and have used tons of bedec barn paint over the years. Maybe coating any cladding I end up getting both sides before install would be the way to go

 

[mrrusty]

why not use cement plank cladding and never have to worry about rot or painting again?

 

[Wils81]

why not use cement plank cladding and never have to worry about rot or painting again?

Went for planning to get to 3m. Wanted a cedar front and composite sides and back, planning officer wasnt keen on mixing materials. Wouldn't even allow 3 sides timber and the back in metal sheets, even though the house to the rear has 5 metre high screening trees