Obs Wall Cladding

[malc-c]

Hi,

I'm in the process of working out how much timber, bricks etc I'll need for the planned observatory. The cost of tonge and grove shiplap cladding is astronomical (sorry for the punn) given the observatory will be 4.8m x 2.4m. One alternative would be to use exterior ply and then rough cast (santex) the outside.

I see that most builds use shiplap cladding, but wondered what peoples thoughts were on using ply ?

[Nillchill]

I've been looking at cladding for a no Astro project at home and found this

CHEAP DECKING ./CLADDING AT A ONE OFF PRICE Greenhouses, Sheds, & Gazebos for Sale EGHAM HEATHROW London

may be worth a call - he's too far away from me

[malc-c]

Nice find - thanks

[JCJC]

Mal, Shuttering ply tends to be good (better) one side and is used to fence off building sites ect 18mm and not to expensive, or sterlingboard which is that orrible stranded stuff but has some exterior treatment. Would think shuttering would be stronger, would (will) use 3x2 frame. (& seen one of your earlier posts-keep mdf out of it). You can always overclad later.

Jordan's dad

(we are coming to this stage soon, just clearing a space in the garden now)

[malc-c]

Thanks for the suggestions. Comparing the prices now

[callump]

I used sheets of OSB (Oriented Strand Board - probably the orrible stranded stuff mentioned above) for the walls of my obsy. It has lasted 10+ years and only now is the south wall needing replacing. Not as attractive as other options but a lot cheaper - and when painted with good green paint (Sadolin), does not look too bad.

Callum

[Digz]

If you are using ply you have two options:

External Grade Ply - this will need an overcoat of something to weatherproof it - render for example.

Marine Grade Ply - this can be left exposed.

It depends on the aesthetics you want really?

Im guessing you are building a brick plinth to sit a timber frame onto? If so don't forget to ensure you sit the frame on top of a DPC (damp proof course) to ensure no rising damp can get to the frame and deteriorate it over time.

Are you insulating the obs?

Ive been itching to draw up a design for an obs but I keep putting it off until we get our own place and then I can design one specifically for that rather than a generic one.

[malc-c]

Digz,

Thanks for the comments. I'm in two minds. Using standard T&G shiplap would make the obs look like a shed and less obvious than if it was clad in ply and rendered, but the cost of cladding a 16 x 7 foot box with T&G is quite costly.

Thanks for the tip about the DPC

[Digz]

Hey Malcolm, no worries

I can see the benefit of cladding in T&G and disguising the obsy but I can imagine it would be quite costly.

Im racking my brain to see what other cladding options there are, but being an Architect working in a commercial practice the only things that spring to mind are probably going to be more expensive than T&G!!! Ill have to think on....

[malc-c]

I should be able to come in on budget if I clad with T&G, but it's tempting to get half a dozen large sheets of 9mm exterior grade ply for 1/3rd the cost and use the money saved for some other goodies (like new laptop )

[Digz]

mmm interesting dilemma.

External grade ply should be fine but I would definitely consider painting it with some sort of weatherproofing paint.

Out of interest, what size timbers are you using for the frame?

[Tim]

Hi,

Your obsy is about the same size as mine. I bought 19mm x 100mm x 4800mm shiplap boards, and had the pressure treated with a clear preservative. I forget the exact price but it wasn't too bad, and the whole obsy cost me less than £1100.

The lines on the cladding hide a multitude of sins, and as the building settles etc it will shrink to fit, but a ply cladding will tend to emphasize any warping or flexing/shrinkage of the frame, and may not necessarily adapt as well.

I did use ply on mine too, just to line the inside of the warm room

If you would like some pics, just ask, or pm

Tim