the yesyes observatory - let the planning begin

[Chris]

One thing I wonder with RoR obsy is how often you actually need to fully open the roof? It would be nice if you can use the RoR as protection from wind etc., when viewing south (or anywhere) have the roof pulled so that it covers most of the scope - should help with dew as well. Viewing north or around the zenith is a different matter but I think the obsy can be designed to help the observations rather than just a cover for a scope on a pier...

A dome will give the best protection but I don't see why a RoR cant be designed to provide better shelter in-use.

I guess it depends on the size of your blue print to some extent and the orientation you might be forced to use, mine is roughly 6'x4' for the warm room and 6'x6' for the viewing area with a roof that rolls west. Like youself I thought I won't need to open it fully and it will be nice and cosy. Once I had built it and rolled the roof fully back over the warm room giving a clear sky of 6'x4' ish give or take an inch. I noticed that this sounded bigger on paper than it looked in reality, especially If you add to this the height of the RoR your trying to look over. I thought in my situation that it could perhaps impinge too much on viewing/imaging, my solution is to extend the rails a bit further out with the brackets which should do the trick.

Hopefully Chris won't need to open his RoR fully so he can have a bit of shelter:) but it might depend on a few compromises he may be forced to make on the way?

Chris

[fwm891]

Chris, I drop!! mine (flap) down the outside of the south wall and just lift it back up and it fits between the east & west walls with its ali skin covering the joins so it remains waterproof. I will be fitting a couple of brackets to the south wall so it doesn't drop too far and may even still show above the level of the fixed south wall so its easily accessed.

[fwm891]

I guess it depends on the size of your blue print to some extent and the orientation you might be forced to use, mine is roughly 6'x4' for the warm room and 6'x6' for the viewing area with a roof that rolls west. Like youself I thought I won't need to open it fully and it will be nice and cosy. Once I had built it and rolled the roof fully back over the warm room giving a clear sky of 6'x4' ish give or take an inch. I noticed that this sounded bigger on paper than it looked in reality, especially If you add to this the height of the RoR your trying to look over. I thought in my situation that it could perhaps impinge too much on viewing/imaging, my solution is to extend the rails a bit further out with the brackets which should do the trick.

Hopefully Chris won't need to open his RoR fully so he can have a bit of shelter:) but it might depend on a few compromises he may be forced to make on the way?

Chris

Chris (yesyes)'s obsy is like mine basically north-south. Luckily I can roll my roof back to the north to open it, south to close.

[fwm891]

Chris - Fly-in-ointment time! Could you not build your pier into the end of the long curved wall and shift your whole build sideways? Its only a raised flower bed after all - Agata wont mind

[Chris]

Drop down does make perfect sense if you've got clear horizons, ah Chris did say his garden slopes down towards the south so he should be quids in and shouldn't have to worry too much about how much his roof opens to the sky. Thats good news then:)

[yesyes]

Yes, I'm quite happy it will be (roughly) north - south aligned. The garden itself does not slope or very little. All gardens south of mine are a bit lower than the previous one.

Francis, somehow I think that Agata will not agree to that. Besides, I wouldn't want a wall going through my warm room.

One alternative is to remove the wall. Agata would agree to that. Just not sure what would be easier, to remove it or to work around it. It looks like dry wall from the outside but I don't think it is. I see concrete/mortar on the inside where the shrubs are. I removed a water feature that also had a bit of this wall (half as high). To remove about a metre and a half of that wall took 2 people almost a day and a trip to A&E.

I'm not too worried about views to the north as long as I can still see Polaris. There is another tree in the next but one garden to the north blocking a bit of the view.

Chris, I do quite like your roof. I think mine will be very similar. Does your warm room roof slope? It's hard to tell from the pictures.

[fwm891]

.... I wouldn't want a wall going through my warm room.

Put a board over it and make it a desk :grin:

I'd go with building over the wall, you're not taking away that much of the working area and you will use the available space to its fullest extent. One thing I've found when building mine is that I've built to about 500 mm of the boundary fences on two sides and any closer and there's no way of getting access to fix cladding etc. If you intend building up to the boundary then make your walls in finished (exterior) sections that can be fixed to foundations from the inside, your only problem then will be on-going maintenance as weatherproofing etc needs re-applying in years to come...

Good luck sir

[yesyes]

Just a though regarding building very close to the fence / boundary. I wouldn't want to lose any space by leaving half a metre gaps on either side.

Would it make sense to use PVC cladding on the 3 sides that are on the boundary? It would need no preserver / weather proofing applied over the years. I would then only use timer cladding (shiplap) on the front to make it look nicer.

[Gina]

Just a though regarding building very close to the fence / boundary. I wouldn't want to lose any space by leaving half a metre gaps on either side.

Would it make sense to use PVC cladding on the 3 sides that are on the boundary? It would need no preserver / weather proofing applied over the years. I would then only use timer cladding (shiplap) on the front to make it look nicer.

I was just about to say that It's expensive but very good - I've used it on the south wall of our back porch - I expect I showed it to you when you came to help me with my obsy. With that you'd only need an inch or two gap to apply preserver to the trellis. Or OTOH i wonder if the obsy wall could act as the boundary fence.

[George]

That tree stump may cause you problems in a year or two as it decays, as they decay underground they will cause subsidence and create cavitys. We had a tree next to the drive and 3 years after it was felled caused part of my drive to dip

At the very least you want to keep your pier as far aways as possible from it.

[JCJC]

I could make it slide down .

Like the top part of a traditional sash window, on a modern spring system would be possible, three unseen walls could be same as Gina's roof - rubber sheet stuff over ply, wrap the edges - waterproof - may need venting? and may cost as much as plastic cladding.

JCJC's Dad

[Gina]

three unseen walls could be same as Gina's roof - rubber sheet stuff over ply, wrap the edges - waterproof - may need venting? and may cost as much as plastic cladding.

JCJC's Dad

I think the rubber roofing would cost more but I'd have to do some calculations as I think it might be close. One thing about the upvc shiplap is that you can nail it straight onto a framework with quite wide spacing as it's reasonably rigid in itself. It's also thermally insulating (but so is wood). The rubber roofing would need to be glued onto OSB or plywood. I think that itself would make it dearer than upvc shiplap cladding.

[Chris]

Chris, I do quite like your roof. I think mine will be very similar. Does your warm room roof slope? It's hard to tell from the pictures.

Hi yes Chris I've built it to slope down towards the front of the obsy away from the seem between the roof and the warm room. It slopes down about 1.25" over 3' 8" which makes it about a 1 in 35 slope. When you look at it closely in the flesh you can see the slope but its quite gentle and I was a little worried about water pooling on the roof, luckily I've had no water pool on the roof and no water ingress into the obsy depsite some bad rain so the design seems to do the job:) I should perhaps point out that the gentle slope becomes much steaper underneith the DPC flap, it rises about 2" at the very begining of the fxed roof to ensure that any water that manages to get under the DPC flap does not get any further in:) I guess a hocky stick side-on would be a good analogy for the side profile of my fixed roof.

[yesyes]

Thanks Chris. That's what I had in mind too. Quite similar to Gina's roof as well.

Regarding PVC cladding, This should do the trick I would think?

http://www.nationalplastics.co.uk/gb/product/__FF312W__/C003/EXTERNAL%20CLADDING/10mm%20Hollow%20Cladding/300%20mm%20X%205Mtrs%20Hollow%20Soffit%20/%20Cladding%20White

[Chris]

That pvc cladding looks very interesting, I've not come across anyone using it on an obsy before but it certainly looks like a good option from a maintenance point of view, the stuff lasts for years!

[yesyes]

They now also do this in Mahogany coloured, though a bit more expensive.

http://www.nationalplastics.co.uk/gb/product/__FF112WG__/B010/SOFFITS%20BOARDS/10mm%20Hollow%20Soffit%3Cp%3EMAHOGANY/300%20mm%20X%205Mtrs%20Hollow%20Soffit%20Mahogany

I might consider using that for the front.

Roughly how much would that cost if it was timber? Considering it's 300mm wide I would need 2 timber lengths for each PVC length...

[Chris]

I'm not keen on dark colours for the outside of obsy's purely from an Albedo point of view, this stuff would get pretty hot in the summer.

[Gina]

Yes, that looks alright. I got some similar looking stuff from Wickes and it said it was unsiuitable for outdoor use But that says it's for soffits so must be alright outdoors. The Wickes cladding was for indoor decoration. Maybe it's a different plastic.

[yesyes]

That tree stump may cause you problems in a year or two as it decays, as they decay underground they will cause subsidence and create cavitys. We had a tree next to the drive and 3 years after it was felled caused part of my drive to dip

At the very least you want to keep your pier as far aways as possible from it.

That's some good advice. Thanks George. I hadn't thought of that...

[yesyes]

Here is a panorama image of the views from the approximate pier position. There are a few trees around but all in all not too bad I think...

[fwm891]

Here is a panorama image of the views from the approximate pier position. There are a few trees around but all in all not too bad I think...

Not bad at all Chris.

[dmahon]

An arbortech can take the stump below ground (first cut it as close to the ground as possible with an old chain).

[LongJohn54]

Just to throw a spanner in the works, how about hiring one of these micro diggers http://www.takeuchi-mfg.co.uk/excavators/tb108.html (and a driver?) for a few days?

You could remove some of the walls and raised bed, clear the ground (and stump) and dig the obsy foundations and pier hole. You could then bulid a normal rectangular obsy without compromising its strength and rigidity (essential for a roll off roof) and give you the maximum space inside to work. At 5m * 2.75m you could leave a little space to get along one side and round the back for maintenance too.

Once completed the walls and raised bed can be rebuilt (if you want them).

John

[yesyes]

Some updates...

We have decided that the north part of the stone wall will be removed. (The conifers will be planted a bit closer to the house). So I will not nee to build around that wall and can make the front of the obsy straight.

I'll try to remove the wall myself but may have to call in a professional as that wall is pretty sold. It looks like a simple dry wall but there is a lot of stubborn concrete/mortar that is well hidden from view. Any volunteers in the Maidenhead area? ;-)

John, I'm afraid that digger would not fit though that narrow path between the walls that will remain.

Then I've decided to use white PVC cladding for the 3 sides that face the fence and a light oak PVC cladding (not the much darker mahogany) for the front.

http://www.ebay.co.uk/itm/270779437130?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

The PVC cladding is a bit more expensive than timber but is basically maintenance free. It also seems to be a lot lighter which makes it easier to handle on a one-man construction site ;-)

For the same reasons I'm now considering clear polycarbonate sheets for the roof.

http://www.ebay.co.uk/itm/270800018842?var=570028030274&ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Again, this is a lot lighter than wood and maintenance free and as an added benefit would let some light in during the day.

Can anyone think of any reasons why I should not use these for the roof?

[JamesF]

I'll try to remove the wall myself but may have to call in a professional as that wall is pretty sold. It looks like a simple dry wall but there is a lot of stubborn concrete/mortar that is well hidden from view. Any volunteers in the Maidenhead area? ;-)

It's amazing what you can (un)do with a 12lb sledgehammer

James