Hinged Roof, Why so few?

[nebogipfel]

Hello All.

Thinking about a permanent home for my swanky C8 NGT (Thanks again Adam ) and I like the idea of keeping it simple.

Domes and Ro-Ro are very nice but what's wrong with a simple pent or apex roof hinged so that it opens in the middle?

I think providing there is a sensible overlap on the join to prevent leaks it should make for a cheap, quickly opened, quiet and above all easy solution to the problem or am I missing something?

Thoughts appreciated .........

[brianb]

but what's wrong with a simple pent or apex roof hinged so that it opens in the middle?

1) Drips are going to be in the worst possible place.

2) The aerodynamic loads on a pent roof are upward creating a tendency to open in wind gusts, so drips are not going to be easy to avoid.

3) OTOH gravity acting on a pent roof with hinges at the eaves is going to make it awkward to operate - much more so than a roof which slides off or rotates as a single unit.

[The Sailor]

My apex roof opens in the middle but slides sideways rather than hinged. Drips were a problem at first but solved this with the aid of three battens with grease which interlocked on roof closure. If it were hinged I would lose a lot of sky and closing it in an emergency would not work, also no extra space required for the roof at sides. When I want to I can close the roof to a slit just like a dome, does have it's uses.

Jim

[nebogipfel]

Thanks Brian, that was quick

I has envisaged a squashable rubber seal on the edge of the overlap and over-the-centre latches to pull the roof tightly shut when closed.

Agreed the roof halves would need to be lightly constructed to make them easy to handle.

[robbieince]

Hi - this type of roof is exactly what I have in my obs.

I am limited by space so decided to go for a clamshell type of opening roof instead of a roll off.

My roof is an apex type not a pent (single slope angle?) with the hinges at the eaves. the problem area is of course the apex where I have an overlap of about 4 inches. This necessitates that the roof is of as lightweight yet rigid enough a material as possible - I used 3 layer marine ply.

The apex is formed of an aluminium channel (for plasterboard applications) opened out to the required angle and bolted to the roof leaf and silicone sealed.

Attached a couple of old pics to get the idea. I have replaced the felted roof shown here with the marine ply version now (mainly due to weight) and extended the overlap from the original 2 inches.

So far works a treat and not a leak in sight.

[The Sailor]

Sorry said pent instead of apex, anyway, Rob like that, it affords you protection from light from thoses houses and you certaily appear to have an allround view.

Jim

[Merlin66]

Any hinged roof I've seen has suffered due to the need to counterbalance the roof. There are some elegant designs but they all need large counterweights.

[nebogipfel]

Any hinged roof I've seen has suffered due to the need to counterbalance the roof. There are some elegant designs but they all need large counterweights.

I'm thinking of perhaps a 7ft x 7ft "shed" so the roof panels would only be 7ft x 3.5ft flaps.If they were stiff but light I can't envisage too many problems opening them

Rob, your observatory is neat, just the sort of thing I was thinking of but possibly pent rather than apex to avoid the gable points sticking up while open......it would be quite simple, of course, to have the gable ends hinge down when open too.

[robbieince]

Mine is 7 foot by 6 foot six and has no counterweights.

If the dimensions grew significantly weight would be an issue. I have ropes attached to pull back beyond vertical when closing and the current sizes are easily manageable.

My gable ends are ok as I have a small tree and my garage adjacent so I lose nothing.

Pm me if you need any help or info.

Regards

Rob

[brianb]

roof panels would only be 7ft x 3.5ft flaps.If they were stiff but light I can't envisage too many problems opening them

A 7' by 3.5' "flap" is more than I'd care to try to move against the sort of winds that are usual in these parts ...

[robbieince]

Agreed but if it's that windy I ain't observing.

[nebogipfel]

Agreed but if it's that windy I ain't observing.

I don't intend to battle the elements either

Appreciate the input so far guys.