Plywood or MDF to make a tented ceiling?

[JoceAndChris]

Carpenters! We're about to order the wood for our tent room project, and can't quite decide what thickness and type. Any suggestions?

The shape of the ceiling is to be an inverted pyramid, created with solid panels that are supported by the long pieces running round the walls.

The panels will be covered with cloth. (as will the walls)

As you can see the pitch is shallow due to the window height which we didn't want to crop. The plan is two put up two long rectangles to make an apex ceiling, like your normal tent. And then to fit in two perfect triangles of wood to turn it into an inverted pyramid shape.

The first image in this link is an inverted pyramid ceiling, I think.
http://www.fauxology.com/2012/03/tented-ceilings/

Thanks for any thoughts on which wood to order.

 

[tycarregydwr]

I'm sorry I have no idea, but I'm very curious - why are you making a tent ceiling, is this purely an aesthetic thing or is there another reason?

 

[plasticpigeon]

How about a wooden frame and plasterboard?

 

[Lime]

MDF is heavy and not as strong, like for like, as plywood.
For those reasons alone I would not use it.
Thin MDF board is likely to snap in half easily and will almost cetainly buckle and belly over time particularly if the room is ever damp.
Plywood (good quality marine ply) will keep its overall shape far better particularly over long unsupported spans.

Personally I'd use battens to give rigidity no matter what you choose. (scewed to back of board edge-on).

 

[JoceAndChris]

Hi tycarregydwr

I expect you never got to read all the posts about wanting to make a Regency cottage ornee and then pimp it out as a location. I've made a Print Room, am onto this campaign/tent room and will fololow with a shell grotto at some point. It is just an aesthetic thing, however, after a recent holiday in France where every single chateau we stayed at had fabric walls I'm coming to see the sense of this more and more. Those Frenchies are onto something! The old plaster is left intact, messy, and dented, and new wiring isn't chased in neatly very often. The fabric is seamed in widths, and applied to huge cardboard sheets which are fixed to the wall. It goes over a thinnish interlining so providing the walls with some degree of insulation whilst remaining breathable to a degree. The fabric doesn't show scuffs, and is simply vacuumed on a yearly basis. I will try and upload some pics.

I am also thinking that insulation could go above my tented ceiling below the real ceiling.

How about a wooden frame and plasterboard?

Isn't plasterboard very heavy? :? Heavier than thin ply?

 

[JoceAndChris]

MDF is heavy and not as strong, like for like, as plywood.
For those reasons alone I would not use it.
Thin MDF board is likely to snap in half easily and will almost cetainly buckle and belly over time particularly if the room is ever damp.
Plywood (good quality marine ply) will keep its overall shape far better particularly over long unsupported spans.

Personally I'd use battens to give rigidity no matter what you choose. (scewed to back of board edge-on).

Thaks Lime I'll read that out to Chris. Very kind of you.

 

[JoceAndChris]

In every case this is fabric on the walls above dado height.

I had a long chat with Madame at Chateau Verrieres, a place I can't recommend highly enough for blissful luxury and the very warmest of hospitality ( http://www.chateau-verrieres.com/), and Madame said her hanger could come to the UK for a reasonable fee. I'm trying to find an English company but I don't think the method is the same, though I'm still trying to get tothe bottom of specifically how it's done in the UK. Obviously you want a nice firm fixing for radiators, lights etc, it's no good having the fabrci actually hanging away from the walls. In France it looked exactly like wallpaper but it was fabric backed with card.

 

[JohnB]

Would a timber frame with canvas attached work? It would be much lighter.

 

[tycarregydwr]

that's very interesting, thanks for the explanation.

 

[Moo]

Have you thought of using spray glue to attach the fabric to a card/paper backing?
I know it works well with small pieces of textile (even chiffon!), but have never tried it with the sort of areas you're contemplating.

 

[worms]

I'm with John B, if you are going for the tent effect, why not drape it as a tent? Fabric on a board will surely always look like fabric on a board? If you need to board it, osb might work out marginally cheaper than mdf.

edit - actually thinking this through, the cost of the boards would probably be offset by the extra cost of thicker material to get the right tent effect, so, Joce, I guess your approach is better after all!

 

[JoceAndChris]

Have you thought of using spray glue to attach the fabric to a card/paper backing?
I know it works well with small pieces of textile (even chiffon!), but have never tried it with the sort of areas you're contemplating.

In your experience does the glue ooze through or darken the colour in patches where glue is thicker at all? It's an interesting idea. Bit stumped on it really. Staples?

I'm with John B, if you are going for the tent effect, why not drape it as a tent? Fabric on a board will surely always look like fabric on a board? If you need to board it, osb might work out marginally cheaper than mdf.

It's very tricky. Various models have failed. Chris hates this, I think because it's too frilly and ruched although he will say he hates it because he thinks it messy and cobweb trapping between the folds.

http://www.gnbespoke.co.uk/tented.htm

There's the simple idea of a pole supporting cloth just like a tent does, to make an apex shape. Again I've had problems with Chris on this one as he thinks a spark from the fire may ignite the whole flappy ceiling. The only way I could persuade him that fabric was a good idea was by going along with the notion that effectively it will be used as a kind of wallpaper, after being moth and fire proofed.

A lot of the mood of a Napoleon style campaign tent will be created with a fabric cornice, which I'll make. The mitred triangular sections of the striped cloth (the stripes opposing each other, if that makes any sense) will hopefully create the illusion of the pitch being steeper than it really is.

http://www.etsy.com/listing/57850288/tented-conservatory-print

People do create some astonishing shapes with tented ceilings and I can only imagine the fabric is attached to wire much in the way a lampshade is made.

http://pinterest.com/pin/178244097722127858/

 

[Moo]

No, Joce, there's no chance of the glue oozing through the fabric, even something as fine as chiffon, that's the beauty of it. You spray a fine mist of the glue on to one surface (the backing) and let it dry out a bit until it feels tacky, like sticky-backed plastic and the like. Then you lay the fabric on the backing and it sticks where it touches.
The only thing that can spoil the effect when using a constructed textile is not laying it onto the backing evenly. It's all too easy to stretch it in places, which means that you can end up with nasty pleated bits.

 

[JoceAndChris]

Gosh, how interesting. Thanks Moo. I shall certainly remember that and try it out for covered pelmet boards and the like. Maybe even for the cornice in this room, if I end up gluing the shapes onto lengths of cut card. For the fabric walls and ceiling in this room, though, I really hope just to hand it over to the professionals. It may be that they instruct me to purchase a paper backed cloth, as this company offers.

http://www.marvictextiles.co.uk/usage/wall-coverings/

If anyone has done a fabric room I'd be very interested to hear from them.

 

[Flyfisher]

Interesting project. I guess a lot depends on how strong the structure needs to be - my guess is not very strong so I tend to agree with Lime that MDF will be too heavy (well, far more heavy than necessary) and I'd go with a fairly thin plywood on a decent frame. I once built a Canadian canoe using thin plywood (4mm I seem to recall, or thereabouts) and it was easily strong enough for two adults, so I doubt that anything stronger would be required for a false ceiling, especially one built onto a frame. Another advantage would be lightness - something not to be underestimated when lifting reasonable large sheet materials into place. Also, think ply would be capable of being formed into curved shapes if desired (might be helpful when trying to simulate a tent?).

 

[billybuntus]

Am I missing something or are you building a false ceiling covered in fabric?

I'm not sure why you would want to do that and reduce your ceiling height but each to their own.

Timber frame and 9.5mm plasterboard. Use tapered edge board and easifill to plaster over the tapers. Sand back and voila

 

[JoceAndChris]

Thanks for the lovely ideas- that's great. Will throw all this in the pot and see what his Lordship says.

Billy- I'm 5ft, my ceilings are almost 9ft and even with reduction will be 7ft -8ft.

I appreciate it probably sounds quite mad.

 

[eezageeza]

I'm with Billy - build a firm frame - 3"x2" timber should do it - then line with 9.5mm plasterboard. That way all the precision cutting will be on easily handled bits of timber; the plaster board fit will be less critical (which is good because it is heavy and awkward stuff) as any joins/gaps can be filled!

 

[Flyfisher]

I appreciate it probably sounds quite mad.

Mad? Of course it's mad. Wonderfully mad!

 

[billybuntus]

Thanks for the lovely ideas- that's great. Will throw all this in the pot and see what his Lordship says.

Billy- I'm 5ft, my ceilings are almost 9ft and even with reduction will be 7ft -8ft.

I appreciate it probably sounds quite mad.

Do you have some example pictures of what your trying to achieve? Very mad but I'd seen worse

Don't use timber boards for your ceiling. It will be heavy and awkward to fit and very difficult to make good of (seamless joints etc).
Not to mention the fire risk factor. Plasterboard will be half the price, half the hassle and look 10 times better.