JamesF's observatory build

[Astrokev]

+1 for EPDM.

Had no trouble with my warm room. Hoping to get the scope room roof on in the next few weeks, weather permitting. Hopefully that'll go OK also, although it's a much bigger area, and there's the apex to negotiate!

[Gina]

What I did with the apex was to lay the sheet over the whole roof and make sure there was enough extra all the way round to tuck up underneath, then fold back one side and apply adhesive from the ridge down a foot or so.  Laid the rubber over the adhesive and rolled down carefully avoiding causing any bubbles.  After that I worked my way down that side to the edge.  Then did the same for the other side.  I used a wallpaper roller to roll down the EPDM to ensure good adhesion.  To spread the adhesive I use a paint roller on a long arm - the sort used behind radiators.  Being water based, the adhesive was washed out of the roller with water immediately after use.  It wasn't allowed to dry during application either.

Edited October 16, 2018 by Gina

[Astrokev]

3 hours ago, Gina said:

What I did with the apex was to lay the sheet over the whole roof and make sure there was enough extra all the way round to tuck up underneath, then fold back one side and apply adhesive from the ridge down a foot or so.  Laid the rubber over the adhesive and rolled down carefully avoiding causing any bubbles.  After that I worked my way down that side to the edge.  Then did the same for the other side.  I used a wallpaper roller to roll down the EPDM to ensure good adhesion.  To spread the adhesive I use a paint roller on a long arm - the sort used behind radiators.  Being water based, the adhesive was washed out of the roller with water immediately after use.  It wasn't allowed to dry during application either.

Thanks Gina. That's the method I used for the warm room and it worked well. I'm just conscious that each side of the ROR is quite a bit bigger and trying to manhandle that much EPDM while not letting the adhesive dry-off too much will be more challenging!

Wrestling with an octopus is an image that springs to mind!

[Gina]

Yes you might need some clips or clothes pegs to hold it up while you apply adhesive in strips.  Or maybe someone to help you.  My roof was 4ft x 8ft each side - one sheet of marine ply each side on top of the framework.  Sometimes I've used broomsticks and G clamps to advantage.  Or in this case I had lots of odd lengths of timber.

[Astrokev]

5 hours ago, Gina said:

Yes you might need some clips or clothes pegs to hold it up while you apply adhesive in strips.  Or maybe someone to help you.  My roof was 4ft x 8ft each side - one sheet of marine ply each side on top of the framework.  Sometimes I've used broomsticks and G clamps to advantage.  Or in this case I had lots of odd lengths of timber.

Yes, lots of timber on hand to hold back the avalanche of rubber may be the answer!

Fortunately, now the weather's cooling off a bit, the adhesive shouldn't dry too quick. I did the warm room in blistering heat and it was drying before I could get it off the roller. (Actually more chance of it being washed off before it dries!)

And apologies James for taking over your thread a bit. I should really continue this discussion on my own thread!

Edited October 16, 2018 by Astrokev

[JamesF]

No problem

I bit the bullet earlier this afternoon and ordered the EPDM and most of the other bits I need to complete both sections of the roof.  Just need to finish off with some hardware from Screwfix, but I can nip into town and get that if necessary.  Or get my wife to pick it up when she does the school run

I also ordered ply for the floor so I have it here to go in as soon as I'm ready, which should make things a little safer when I'm walking around inside.

James

[Astrokev]

33 minutes ago, JamesF said:

No problem

I bit the bullet earlier this afternoon and ordered the EPDM and most of the other bits I need to complete both sections of the roof.  Just need to finish off with some hardware from Screwfix, but I can nip into town and get that if necessary.  Or get my wife to pick it up when she does the school run

I also ordered ply for the floor so I have it here to go in as soon as I'm ready, which should make things a little safer when I'm walking around inside.

James

Good progress and planning ahead there.

As regards the floor, I decided to dice with death and am still walking on the joists. Lost count of the number of times I've slipped and twisted my ankle.

[JamesF]

I've fallen through a couple of times myself

I had some scabby old offcuts of ply lying about so after the first time I put those down to give a bit of a walkway.  Still managed to fall through once more though   After that I learned to be more careful...

James

[Gina]

I did the floor of mine before most other things - certainly before the roof.

[JamesF]

15 hours ago, Gina said:

I did the floor of mine before most other things - certainly before the roof.

I've made the roof the priority on mine because once that's done I have loads of stuff inside I can get on with over the winter months, and some of that work such as building the piers and running ducting to them from the warm room (which will be below the floor) needs to be done before the floor is laid.  And of course once the space is relatively rainproof I can have leave temporary lighting in place to allow me to work later in the evenings.

James

[Gina]

I bought a giant tarpaulin for shelter and lots of rope!  That formed a huge tent to work in.  Just a roof wouldn't have sufficed as we get plenty of horizontal rain here.

[JamesF]

1 minute ago, Gina said:

I bought a giant tarpaulin for shelter and lots of rope!  That formed a huge tent to work in.  Just a roof wouldn't have sufficed as we get plenty of horizontal rain here.

I'm hoping that wrapping the walls in breathable membrane should deal with most of that, though I'm not averse to the idea of getting a load of cladding here and fitting it as and when the weather allows.  At least, once I have decided what cladding I am going to use.  Whilst shiplap certainly looks very smart, it's almost too smart and insufficiently "rustic" for a rural location such as this and I'm tempted to go for feather-edge or waney-edge boarding.

James

[Guest]

This is shaping along very nicely James, its always an adventure building your own isnt it pal  i look forward to the next pics.

[JamesF]

EPDM arrived today, along with the bits from Screwfix.  Hopefully the OSB should turn up tomorrow.

James

[JamesF]

Well, the ply for the floor arrived today, but not the OSB :(

I think I have enough OSB lying about to do the warm room roof so I may try to get that done this weekend, but the rolling roof will have to wait another week by the looks of it.

James

[Guest]

All good things come to those who wait and all that ??? it's a killer waiting though eh. Looking forward to the next install of pics James.

[Stub Mandrel]

Cripes, I've only just discovered this thread.

Well done James!

[JamesF]

10 minutes ago, LeeRich said:

All good things come to those who wait and all that ??? it's a killer waiting though eh. Looking forward to the next install of pics James.

I have a fair few non-astro things to get done this weekend and there are other jobs that can be done on the build as well so I'm not going to stress about it.  If the OSB turns up next week (which really should happen) then I may even still meet my target of having the roof on before the end of October :)

James

[JamesF]

15 minutes ago, Stub Mandrel said:

Cripes, I've only just discovered this thread.

Well done James!

Thank you, Neil :)

James

[JamesF]

What a gorgeous day!  Was stuck inside for the early part of the morning, putting up shelves and the like, but it was definitely shorts and t-shirt weather by the time I went out to put away a delivery of chicken food and then start work on the observatory.  The insects were clearly making the most of things too.  I think I saw more wasps today than I have done all year, and when l looked back towards the house when the Sun was over the roof at around 3pm I could see huge clouds of small insects caught in the sunlight.

First job today was to slip some DPC material under the roof rails and then start fixing the rails down.  I used some zinc-coated "self-tapping" hex head coach screws for the rails, which meant I could put them in using the drill and a socket.  With the first rail on each wall fully fixed down and the second loosely fixed I could work out how much more I needed to allow the roof to open fully -- just another 20 to 30 cm as it turns out, so I'll cut a couple of pieces long enough to have a set of fixing holes at each end.  I've left the second rails loosely fixed for the time being as I'll need to lift them when the EPDM goes on the warm room roof.

Although the OSB I ordered wasn't delivered this week I found two and a half sheets plus some smaller offcuts in one of the sheds, probably left over from building the beer shack -- nowhere near enough to do the rolling roof, but plenty to cover the warm room.  So for the rest of the afternoon that was what I did.  One sheet did most of the job and then the cutting took more time than anything else.  I still have a little more woodwork to do before I put the EPDM on, but I'm hoping I can get all of that done tomorrow.

It feels so good to be actually putting roofing on at long last :)

James

[ollypenrice]

On 14/10/2018 at 13:58, JamesF said:

Just discovered a slight negative side to using metal sheeting for the roof: the cost of delivery.  Even the closest place I've found so far want to add over 25% to the order for delivery (because it's a fixed price and I don't need that much).  I might have to look at how practical it would be to pick them up.

James

I pick mine up on the Duster's roof rack. Just be careful to prevent the sharp edges from sawing through any tie downs that you use. This certainly happens, as I know!!! 

I've used flat steel sheet on our summer kitchen's fixed parasol but you have to bolt it down only at one end and hold the rest down under wooden or steel strips which allow it to expand without buckling. Why does corrugated steel not buckle along its length? Maybe it tries to but the corrugation simply prevents it. Expansion in the other axis can be absorbed by deepening the peak to valley, of course.

This is a great observatory in the making. 

Olly

[Astrokev]

Looking great James ? 

[JamesF]

I ordered my EPDM in a single hefty 40kg piece as the width I needed for the warm room roof was very close to the length I needed for the roll-off roof, so the first (slightly scary) job for today was to unpack the EPDM, lay it out and cut the right size piece off the end for the warm room.

I'm surprised by how bright it looks in that photo.  It's really quite a dark grey.  Anyhow, I took far longer than strictly necessary to measure up, making sure the remainder would definitely fit the rolling roof and then checking again, mistakes at this point being rather costly

I still needed to put the lip on the top edge of the roof to help stop rain or snow being blown underneath, so I got that done, fixed a few other bits and pieces that couldn't be done after the roof was on and then broke out the adhesives and worked on each side of the roof separately, using the roof rails to keep the EPDM taught.  Thanks to the lower temperatures at this time of year I didn't have to rush too much with the contact adhesive either, and in fact where there will be spare rubber to trim off I've temporarily stapled it to the woodwork to keep the EPDM in place whilst the adhesive dries.  The negative side of the lower temperatures was that the creases didn't want to drop out of the sheet so easily.  I'll have to see how that goes when it comes to doing the rolling roof.

Unfortunately I didn't quite have time to finish off at the top and bottom edges, so I've clamped those in place for the time being and hopefully I'll get to them during the week as it looks like we're forecast a few more warm days.

Too late I realised that the spare bit of 3x2 that I used for holding the top edge in place was just too wide to allow the rolling roof to pass it so I wasn't able to run the roof off and make sure the rails are aligned before screwing them down, hence the clamps holding the rails down at this end

James

[Guest]

This is looking very exciting ??

[Astrokev]

Looking great James. 

I know what you mean being nervous about measuring and cutting the EPDM! I did the same and bought 1 piece to cover both rooms. 

Did you use contact adhesive round the edges, as they recommend, or just the water based adhesive?