Astrokev's ROR - The Build

[Astrokev]

26 minutes ago, yesyes said:

This is my south side.

The black painted (bitumen paint) piece just above the white cladding is the top of the south wall. The one on top of that is part of the rolling roof frame. It overhangs the wall by its own thickness (2 inches, 5cm). The roof overhangs a further 4 inches, 10cm. In 5 years not a drop of water came in that way.

Where I did have a bit of water and snow ingress (small amounts of water twice during really heavy rain, a bit of fresh snow blown in each winter) is where the roof rails go from outside (warm room side) to the inside (scope room side). I have a pair of these huge brushes used to put glue on wallpaper lying around that fit these gaps perfectly. But the ingress hasn't been bad enough for me to bother installing them yet. ?

Thanks Chris. I've just been looking at the pics of your build (cunningly saved to my PC as a reference, since my design is based largely on yours!) and couldn't see any showing the south wall seal - in fact hardly any builders seem to show clearly how they approached this obvious challenge!

Your post above now reveals all ?! Thanks for posting. Your solution looks good. My design currently has an overhang, but that's mainly because I hadn't given it too much thought. I was intending revisiting this to try and come up with a different approach but, having seen your post, maybe I should just leave it as it is!

[yesyes]

You're welcome. ?

Note the cut-out on the left of the roof frame. This is where the roof frame moves over the rail and didn't clear it. I hadn't thought of that and needed to do this cut-out later with a jigsaw with the captive mechanism of the roof already installed (so no way to lift the roof a bit). That was quite tricky to do. I really wished I had fully tested the roof roll-off before installing the sheets and captive mechanism on the roof.

[Astrokev]

Not as much progress today as I'd hoped (that seems to be a recurring theme). Bought the OSB and a 2.4 x 1.2m piece of 50mm foam insulation for the warm room roof, together with yet more studding and brackets. It seems to go on forever.

In the little time left in the day, I added a double joist to support the edges of the 2 pieces of OSB I'll need to use for the warm room roof, and then moved the existing joists to make them more equally spaced. Also added studding across the back of the roof to attach the OSB to. The SketchUp drawing shows the next stage - to add a piece of ply across the back of the roof as an overhang. The holes are for soffit vents (thanks @RayD for this suggestion) which will help ventilate the small space between the insulation and the OSB. I plan to drill largish holes in the vertical timber at the "top" of the roof, that separates the warm and scope rooms, to allow a small flow of air through the roof-space to reduce risk of condensation build-up. Then, finally, I can start to play with the OSB and the EPDM ?.

 

[JamesF]

Anything that moves the project forward is progress, no matter how small

I know what you mean about the EPDM being heavy.  My beer shack uses a single piece measuring 7m by 4m to cover a pitched roof that is probably about eleven feet high at the ridge.  Getting that on all by myself from a ladder was quite exhausting   It has been absolutely brilliant though, so I shall be using it again for my own obsy.

James

[JamesF]

I meant to mention...

My plan is to use a similar stop/seal mechanism on the north end of the roof as you have.  I'm very tempted to add a strip of DPC material or an offcut of EPDM to the bottom edge of the roof as well, positioned such that it just drags along the warm room roof as the roof gets close to fully closed and is hard for the wind to lift up.  Like a draught excluder, basically.

The reason for doing so is that during the snow storms in March the wind actually managed to drive snow upwards between the tiles on our house roof.  We discovered this because the roofing felt (which would normally seal the roof under the tiles) is decaying and allowed the snow through to form quite large heaps on the bedroom ceilings which were then damaged when it melted.  If so much snow can be driven through such small gaps, I'm hoping that my extra sealing strip should prevent snow being driven up the roof and inside the obsy.  The north side of our property is fairly brutally exposed however.  There's nothing to provide a windbreak for, well, forever, really.

James

[Astrokev]

4 minutes ago, JamesF said:

I meant to mention...

My plan is to use a similar stop/seal mechanism on the north end of the roof as you have.  I'm very tempted to add a strip of DPC material or an offcut of EPDM to the bottom edge of the roof as well, positioned such that it just drags along the warm room roof as the roof gets close to fully closed and is hard for the wind to lift up.

Yes, I'd considered something similar. I'm sure the seal between the rolling and fixed roof will not be parallel, no matter how hard I try, so I've been thinking how I could create a "soft/flexible" join as the roofs come together to improve the seal. A strip of EPDM as you suggest could work well I think. 

[Astrokev]

OK, I've been checking out installation of the EPDM from Rubber4roofs and am now wondering whether I've got the correct adhesive ?.

I bought the water based adhesive as recommended on the website, but I'm wondering whether this will be good enough for the edges, and especially for the corners, where I'll need to fold the rubber to form a neat finish (well, as neat as I can).

To anyone who's used EPDM, should I also get some contact adhesive for the corners, or will the WBA stuff be adequate?

Thanks

[Gina]

I think I would advise contact adhesive for the corners.  Mine have come undone and I added extra clamping.  Large headed tacks can be useful for holding the edges - I wouldn't rely on adhesive.  And I too highly recommend EPDM roofing from Rubber4Roofs.

[Yawning Angel]

I’m planning to use a liquid applied roof coating, which is flexible enough to cover heat expansion and flex in structure as the roof moves. Plus, anything it touches it sticks to ?

[JamesF]

1 hour ago, Gina said:

I think I would advise contact adhesive for the corners.  Mine have come undone and I added extra clamping.  Large headed tacks can be useful for holding the edges - I wouldn't rely on adhesive.  And I too highly recommend EPDM roofing from Rubber4Roofs.

Yes, I'm sure the instructions say to use the water-based stuff for the centre and then the contact adhesive for the outer 150mm or so (could be more than that, but I can't recall).

James

[yesyes]

I didn't know about the contact adhesive when I did my build. I used only the water based adhesive and have not had any issues with it. Except on the south side, my EPDM is just hanging off the roof sheets by about 4 inches / 10cm. It has never lifted off anywhere (my obsy is quite protected from wind though).

Though, if I had to do it again, I would probably use some contact adhesive around the edges, just in case.

If you want to fold the EPDM around the edges of the roof sheets, contact adhesive is a must, I think. I used it for the roof of my fire wood store (built with left over timber from the obsy build) around 3mm ply and that holds very well.

[Astrokev]

4 hours ago, yesyes said:

I didn't know about the contact adhesive when I did my build. I used only the water based adhesive and have not had any issues with it. Except on the south side, my EPDM is just hanging off the roof sheets by about 4 inches / 10cm. It has never lifted off anywhere (my obsy is quite protected from wind though).

Though, if I had to do it again, I would probably use some contact adhesive around the edges, just in case.

If you want to fold the EPDM around the edges of the roof sheets, contact adhesive is a must, I think. I used it for the roof of my fire wood store (built with left over timber from the obsy build) around 3mm ply and that holds very well.

Thanks Chris

[Astrokev]

13 hours ago, Gina said:

I think I would advise contact adhesive for the corners.  Mine have come undone and I added extra clamping.  Large headed tacks can be useful for holding the edges - I wouldn't rely on adhesive.  And I too highly recommend EPDM roofing from Rubber4Roofs.

Thanks Gina, appreciate your advice. Looks like I need to revisit my friends at Rubber4roofs!

Kev

[Astrokev]

Despite being incapacitated with hay-fever today, I managed to complete the soffit and ventilation.

Next job is to cut and insert the foam insulation into the roof and cut the OSB. Now I realise I need contact adhesive in addition to the WBA to stick down the EPDM, playing with the EPDM looks like it'll have to wait a few more days. Never mind; loads of other jobs I can be getting on with.

 

[Astrokev]

22 hours ago, Astrokev said:

 Never mind; loads of other jobs I can be getting on with.

 

Beginning to regret me saying those words. This morning I awoke to find water dripping through my ceiling in the room directly below the family bathroom shower.

So, work on the observatory has had to temporarily taken a back-seat while I try and save my house. At least it will give me a chance to order and await arrival of the contact adhesive for my roof membrane!

[JamesF]

You have my sympathies, Kev.  We have three totally unrelated plumbing leaks since February.  Fortunately all now sorted, but there's still a lot of repair work to do.  I keep telling myself that if I don't look up then I won't know that some of the ceiling is missing.

James  

[Astrokev]

1 hour ago, JamesF said:

You have my sympathies, Kev.  We have three totally unrelated plumbing leaks since February.  Fortunately all now sorted, but there's still a lot of repair work to do.  I keep telling myself that if I don't look up then I won't know that some of the ceiling is missing.

James  

I didn't go into details, but I'm the same. Dodgy copper to plastic join resulted in half my study ceiling coming down last year (all over my PC desk). This is now repaired but I'm still redecorating. The new leak is from a family shower above the same room - big stains and very soggy plasterboard which will need replacing I think. The third leak is from an ensuite shower above a utility room next to the study. This was put out of action just after Christmas when water started pouring out of the light switches whenever you had a shower. I'm no electrician but I don't think this is a good combination.  I'm pretty handy around the house but, frankly, I've had enough. Plumber is coming on Wednesday.

At least it takes my mind off the escalating observatory costs!

Contact adhesive for the EPDM is ordered by the way. Perhaps I can repurpose it to repair my ceiling.

Edited June 4, 2018 by Astrokev

[Dr_Ju_ju]

If you want something lighter than EPDM, and maybe easier to apply\fix would be PVC pond liners e.g.   https://www.pondlinersonline.co.uk/product/pvc-pond-liner/ 

They are very strong, light & watertight and are even used for lining reservoirs, and much cheaper than EPDM. My pond has one & has never sprung a leak in the last 15 years....

[Astrokev]

7 hours ago, Dr_Ju_ju said:

If you want something lighter than EPDM, and maybe easier to apply\fix would be PVC pond liners e.g.   https://www.pondlinersonline.co.uk/product/pvc-pond-liner/ 

They are very strong, light & watertight and are even used for lining reservoirs, and much cheaper than EPDM. My pond has one & has never sprung a leak in the last 15 years....

Julian

Thanks but if you read back on my posts you'll see that I ordered and received delivery of my EPDM several days ago.

As far as I know, PVC has relatively poor UV stability so would have a poor lifespan when exposed to daylight. My intention is to never have to re-roof my obsy!

Kev

Edited June 6, 2018 by Astrokev

[Astrokev]

So, it seems that my shower units are shot, water having gotten behind the wall tiles in both shower cubicles, which are now loose. My friendly plumber says the only solution is to rip out the cubicles and shower trays, remove all the wall tiles and probably the plaster board behind, and retile and fit new cubicles. What joy!

So, to relieve my anxiety, I decided to do some work on the observatory ?.

Time to work on the roof. Hooray. Cut and installed the foam insulation to the warm room and, in shaving the pieces down to fit between the joists, got completely covered in bits of foam due to static. It feels good to be able to stand inside the warm room now that it has a real ceiling (well, I still need to fit thin ply as an inner covering). The images show the design of the ventilation to prevent condensation affecting the inner side of the OSB. The wooden outer covering is a sheet of MDF I was using to clamber over the roof. Apart from being pleased that it took my weight, it also shows the gap between the insulation and what will be the OSB sheets, and how this air gap is ventilated by the soffit vents (just the holes at the moment. I won't fit the vents until after I've painted the obsy). I still need to drill holes through the vertical length of timber at the top of the warm room slope to allow a flow of air through the space.

Pleased to have got this done. Next job is to fit the OSB sheets and start cutting the EPDM. The contact adhesive arrived today so have all the bits. Just need to get a day clear of other stuff. My lovely baby grandson (with his lovely mum) is visiting tomorrow, so looks like Friday's the day ?

[JamesF]

Looking good ?

On the subject of showers and tiling, I will never go there again.  We put in a new en-suite a couple of years back and also replaced the tiles around our main bath/shower with this sort of thing:

https://www.diy.com/departments/splashwall-star-dust-single-shower-panel-l-2-42m-w-1-2m-t-11mm/161489_BQ.prd

(though ours has some sort of man-made backing material, not timber which I'm told is not as good, and came from the local builder's merchant).

Far fewer places to leak, no grout to clean (easier to clean all round), easier to cut around fittings.  Marvellous stuff.  I wish I'd known about it years ago.

James

[Astrokev]

30 minutes ago, JamesF said:

On the subject of showers and tiling, I will never go there again.  We put in a new en-suite a couple of years back and also replaced the tiles around our main bath/shower with this sort of thing:

https://www.diy.com/departments/splashwall-star-dust-single-shower-panel-l-2-42m-w-1-2m-t-11mm/161489_BQ.prd

 

Thanks James. My daughter has something similar to this stuff in her flat and I was indeed considering not replacing tiles - too many opportunities to fail! Expensive stuff though (we have big showers), but perhaps not as expensive as fixing it when it goes wrong!

Edited June 6, 2018 by Astrokev

[JamesF]

Yes, it is somewhat more expensive than some tiles and our showers are relatively large too, but in the end it was a "quality of life" decision and one I have absolutely no regrets over.

James

[Davey-T]

You can get it made completely from plastic with no timber / mdf backing to worry about.

Dave

[Astrokev]

Found a bit of time this afternoon, so was able to nail the insulation in place to prevent it "riding up" and potentially impeding air flow through the insulation-OSB gap. Also managed to bash my thumb and index finger in the process, causing the air to turn blue for a few minutes. Fortunately the spilled blood is out of shot in the attached images. Also drilled a series of rather crude holes (difficult to hold the drill steady with my fingers wrapped in kitchen towel) through the top beam, to connect the roof space (such that it is) to the scope room, allowing some movement of air through the space. At least that's the theory.