Gina's Observatory - The Build

[Gina]

Gina,

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[Anweniel]

Looking great Gina seems you got it 'nailed'...(sorry couldn't resist the bad pun!)

With the cold weather creeping in and the clear nights we've been lucky to have, can only imagine how much you are itching to get the build complete and start the observing

[Gina]

Progress report for today

The day started off with rain but by mid morning the rain had stopped and the sun came out for a while so I have been able to make some progress today, including making up the framework for the east end obsy fold down flap.

From examining the shiplap and the hinges, it became clear that arranging the flap to fold down outwards, as originally planned, was not going to be practical. So I checked the clearance for folding it down inwards and there was something like a foot clearance from the mount - quite sufficient I think. As a result I have decided to have the flap folding inwards.

Today's progress itemised :-

1. Examination of the north side roll off to dividing wall weather-proofing and clearances.

2. Same for the south side.

3. Measured, cut, treated and fixed two top purlins for the corrugated bitumen roofing. There are two more to fit but I need to sort out timber for them.

4. Measured, cut, treated and fixed together the timber pieces for the fold down flap.

5. Attached flap framework to east side obsy wall with three galvanised T hinges.

With today's progress we have photos and webcam images, starting with a couple of DSLR photos of the fold down flap. Then samples of the saved webcam images in chronological order, from a very wet obsy building site and when I first went out to check things, to pics of my various activities on the build throughout the day.

[Gina]

Looking great Gina seems you got it 'nailed'...(sorry couldn't resist the bad pun!)

Thank you

With the cold weather creeping in and the clear nights we've been lucky to have, can only imagine how much you are itching to get the build complete and start the observing

Not arf!!

[Gina]

Started fine this morning (while still dark) but raining now Very mild but windy. I'm hoping the rain will stop later.

[ncjunk]

Nice to see the progress, I can´t wait to see the roof go on and the lapping put on! I wish I had spent more time on getting my roof right but yours looks great.

You´ve done more posts since April than I´ve done since 2008....no fair!

[Gina]

Nice to see the progress, I can´t wait to see the roof go on and the lapping put on! I wish I had spent more time on getting my roof right but yours looks great.

Thank you Yes, I'll be very glad to get those things done too - very much!

You´ve done more posts since April than I´ve done since 2008....no fair!

There's no stopping me once I get going

[Gina]

With plans to go to Wickes in Taunton shortly, I've been working out what I would want for my obsy roof using their corrugated bitumen sheets. Unfortunately it isn't just the bitumen sheets, it would also need ridge pieces for the apex and fixing nails (nearly 200 of them) and that lot comes to £157.39. This is catering for 6 sheets. If I were to use the one just about usable sheet I already have I can deduct £16.49 making £140.90. I thought I had two sheets but one has holes in the wrong places.

Alternatively, if I were to use the EPDM Rubber Roof Membrane (as for the warm room roof) @ £77.12 all in, plus two sheets of 6mm plywood (from Wickes) @ £37.92 the total is £115.04. ie. cheaper.

I could further reduce the cost if I were to use the OSB sheets I already have. However, this would make for a much heavier roof and I don't really want to do that.

Two or three benefits result from using the rubber roofing apart from the lower cost :-

1. It's much easier to fit using adhesive onto relatively light weight plywood rather than the awkward floppy corrugated sheet and nearly 200 nails.

2. No corrugations at the eaves and apex to somehow seal against the ingress of rain or snow.

3. The two roof sections will match better.

[Aoraki]

I would use the EPDM but with either 9 or 12mm ply, go to a timber merchants rather than Wickes, it will be cheaper.

[fwm891]

Second Aoraki on that re: 9-12 mm boards even though you have enough roof timbers for about 3 foot of snow...

[Gina]

I would use the EPDM but with either 9 or 12mm ply, go to a timber merchants rather than Wickes, it will be cheaper.

Had I not already fixed purlins in at 300-350mm spacing for the corrugated sheet, I would use thicker ply. But I think with such good support, 6mm ply ought to be alright. Also there is a 10 degree slope so good run-off. My main reason for using 6mm ply is to keep the weight down.

I will check prices with our local timber yard tomorrow morning.

[Gina]

If 9mm ply is considered the minimum, is it significantly lighter than the 11mm OSB I already have, I'm wondering. I guess the timber merchants will know. I was thinking that 6mm ply would save several kilos over the OSB which would probably be helpful in keeping the weight down but anything much less may not be worth it.

[malc-c]

Both the ROR and Warm Room roof of my observatory are sheeted in 12mm OSB. I'm around 11st and cam walk / sit on both roofs and it's sound as a nut...

[Gina]

Both the ROR and Warm Room roof of my observatory are sheeted in 12mm OSB. I'm around 11st and cam walk / sit on both roofs and it's sound as a nut...

Yes, the OSB is certainly strong enough and is what the timber merchants recommend and use themselves for their shed roofs. As I've already got the OSB I'm beginning to think I might as well use it. In reality I don't think the weight will be excessive - I've built the framework strong enough to support a house I shouldn't wonder It certainly takes my "not insignificant" weight quite easily! (Yes, I have to admit to being heavier than you, Malcolm).

[michael8554]

The EPDM roof seems to tick a lot of boxes.

If you went the corrugated route you can buy polystyrene eaves fillers, at least you can for the clear plastic corrugated systems, they match the curve of the corrugations.

But with corrugated the whole perimeter always looks half-finished and , how can I say, agricultural, whereas the EPDM looks good, "Proper Job" as folk say.

OSB v 6mm Ply - can you use the OSB you already have elsewhere, the south warm room wall f'rinstance? As you say, you've walked on the roof frame without it sagging and popping the wheels off the tracks, so why not go for the light option?

Looking good, luv the flip down top section of the south wall, and the roof sliding over the warm room on non-intrusive rails.

Good luck

Michael

[Gina]

The EPDM roof seems to tick a lot of boxes.

If you went the corrugated route you can buy polystyrene eaves fillers, at least you can for the clear plastic corrugated systems, they match the curve of the corrugations.

But with corrugated the whole perimeter always looks half-finished and , how can I say, agricultural, whereas the EPDM looks good, "Proper Job" as folk say.

Yes, the EPDM certainly makes a very neat and tidy job. 95mm profile eaves filler is available but expensive. Normal eaves filler is 75mm (3"). I was quite surprised at the cost of the extras for corrugated bitumen, I have to say. I didn't expect it to come out more expensive than EPDM. I guess I should have done more exact costings earlier and then I could have saved some cost by buying all the EPDM at the same time.

OSB v 6mm Ply - can you use the OSB you already have elsewhere, the south warm room wall f'rinstance? As you say, you've walked on the roof frame without it sagging and popping the wheels off the tracks, so why not go for the light option?

Yes, I can certainly use the OSB to line the warm room walls. I will be lining them later anyway.

Looking good, luv the flip down top section of the south wall, and the roof sliding over the warm room on non-intrusive rails.

Good luck

Michael

Thank you

[Gina]

Like other timber supplies, our local timber merchant sells 6mm 8x4 sheets at a much lower price than Wickes, not much over half the price. I decided while we were out this morning with the pick-up to call into the timber yard and pick up some plywood - enough to line my warm room walls at least. I shall have a chance this afternoon to compare the weight and strength of the 6mm plywood against the 11mm OSB. Then I shall decide which to use on the roof.

[Gina]

I haven't weighed the OSB or plywood but I had little trouble shifting 10 sheets of 6mm ply off the pick-up and stowing it on edge in the shed - I can lift a sheet quite easily by clasping it in both hands by or near the edge. With the OSB I can just about lift one end and drag it. Yes, the OSB is stiffer than the plywood but with the ply supported every foot I think it would probably carry my weight even! The OSB on the warm room roof is supported every two feet and is very firm.

[Gina]

Daily Progress Report.

A fine and mainly sunny day and I spent much of the morning shopping for stuff for the build. Some brush type draught excluder for sealing the roll off section and the remainder of the guttering and associated fittings. The expedition concluded with a visit to the timber yard to collect 10 sheets of 6mm plywood. I'm using 2 on the obsy roof and the rest for lining the warm room and dividing wall.

To itemised today's progress :-

1. Adjusted some of the obsy roof structure to allow for the change from corrugated bitumen sheeting to the EPDM rubber roofing on plywood construction.

2. Shopping for guttering and other bits plus plywood.

3. Cut guttering and downpipe and fitted them to the warm room roof.

The images today are all from the webcam and cover jobs 1. and 3. above.

[malc-c]

Gina,

Can I suggest that you concentrate on getting the shiplap on, and the ply on the roof and worry about the trimmings like guttering after... try and get the structure water tight first !!

[Gina]

Gina,

Can I suggest that you concentrate on getting the shiplap on, and the ply on the roof and worry about the trimmings like guttering after... try and get the structure water tight first !!

Fair point Malcolm I didn't feel up to tackling the roof this afternoon and the guttering on the warm room roof was a small job I could fit in plus I've been fed up with putting up and taking down temporary guttering

I'm planning a full frontal assault on the obsy roof tomorrow, weather permitting. The shiplap job is planned for Friday but the weather forecast isn't looking very good ATM Not as bad as Thursday though!

I'm hoping to get a clearer forecast for Friday's weather tomorrow and that will be when I shall decide if a work party is on for Friday.

[fwm891]

I was only coming on Friday for the party have we got to work as well :eek:

[Gina]

One piece of plywood screwed onto the obsy roof frame

[Gina]

I was only coming on Friday for the party have we got to work as well

It's not compulsory

Doesn't look like much of a party ATM - just you and me, I think the others might be away. Weather forecast is showers. Maybe we should postpone it until next week.

[yesyes]

Gina,

I'm still willing to help, of course. But I wouldn't have been able to do this Friday. That's why I've kept quiet. ;-)

A weekend would be much easier for me.