Roll Off Roof Question

[kirkster501]

Hello all,

Trying to visualise what the roll off roof looks like close up.   If the roof sits on the four bearing wheels and steel track does the roof then overhang to create a seal in some way to keep the elements out of the obsy when the roof is closed?  I am getting confident I could tackle this myself but just struggling with the roof bit.

I also think a flat sloping roof is maybe an easier proposition than an apex roof.  Whats the consensus of you guys on that one?

[wxsatuser]

I did a flat roof with a slight slope, it over hangs the every side by about a foot.

It is made with 11mm OSB on a heavy C16 timber frame and covered with heavy felt.

I did'nt bother with metal rails the five small angled castors each side just run on the timber beams.

[Bizibilder]

Have a look here:  http://stargazerslounge.com/topic/187362-bizibilders-new-roll-off-roof-observatory-build/   On mine the roof rails are outside the main walls and below the top of those walls.  The roof is designed so that three of its own short walls overhang the runners (and the "back" wall) to provide a "seal".

There is no real seal as such - that is to allow the free circulation of air when it is hot and/or humid - both conditions that can lead to problems - the "gaps" are around 1-1.5 cm or so.  The fourth "seal" is the wall over the door - this slides closed and passes over the lower fixed wall by about 15mm (the thickness of the cladding), a "window sill" was made to fit full width at the lower edge of the small roof wall and this has made the whole thing watertight.  The gap on this fourth wall is around 2-3 mm (millimeters) and has proved to be totally weatherproof.

[wxsatuser]

The actual obsy is just four 4inch fence posts with a concrete footing between each and a deck built on top.

The frame is C16 timber, inner walls are OSB and the outer walls are corragated bitumen sheets.

It's approaching two years old and no leaks so far.

Two pics of construction.

[Starlight 1]

This is the help that I got if any good to you.http://stargazerslounge.com/topic/229339-rolling-roof-wind-speed/

[ollypenrice]

I make the roof and sides roll off to get lower horizons, which are worth having at my site. The sides do, as you mention, drop below the rails.

These are, of course, 'under construction' pics. Although we have a generally favourable climate we are at 3000 feet and get 'serious weather' when we do get it!

In the snowy pic the shed at the rear, partly obscured, is the robotic one. It has a span of over 4 metres on a single pitch at quite a shallow angle. Construction is all timber and it's doing well. Generous roof overhangs have a lot going for them.

Olly

[Gina]

The sides of my roof drop below the running rails too - by about 2" (50mm) or so.  The top edge that moves over the warm room overlaps too with the warm room roof having an upstand of about 3" and the ROR a lip of about 2".  The other top edge overlaps the wall flap when closed.  Where there are vertical edges (I too move part of the side walls with the roof) I have used brush type draught excluder to provide a seal.  No wet gets in even with storm force horizontal rain

[r3i]

Like Gina (in fact I think I got the idea from Gina), I have a lip on the warm room roof that provides sufficient weatherproofing and also acts as stopper to prevent the roof rolling off the structure when opening and closing.

The roof sides overlap the observatory walls by a few inches.

Finally I have a strip of EDPM rubber left over from the roof that is attached to the rolling roof at the gable end and this provides a simple but effective weather barrier.

[Gina]

Looking good - nice neat job

[perfrej]

I make the roof and sides roll off to get lower horizons, which are worth having at my site. The sides do, as you mention, drop below the rails.

These are, of course, 'under construction' pics. Although we have a generally favourable climate we are at 3000 feet and get 'serious weather' when we do get it!

In the snowy pic the shed at the rear, partly obscured, is the robotic one. It has a span of over 4 metres on a single pitch at quite a shallow angle. Construction is all timber and it's doing well. Generous roof overhangs have a lot going for them.

Olly

Yikes! That's a bit of snow on my stuff...

/per