Astrokev's ROR - The Build

[JamesF]

I think I'd have to cancel Christmas in favour of getting the observatory finished :D

James

[Astrokev]

1 minute ago, JamesF said:

I think I'd have to cancel Christmas in favour of getting the observatory finished

James

Don't tempt me

[Alan White]

Oh my oh my, you turn away for a moment and its up and running, nice one Kev.
Yes get the roof secured and the gutters on winter is upon us.
As to cancelling Christmas, oh yes please.

[Gina]

I second that!!

[Rusted]

Humbug?

Do you want ice with it?

[Gina]

No thanks - cold enough already!  ?

[Astrokev]

Every bit of progress is good progress, no matter how small....

Attached the door hook and eye catch this afternoon. Now I can hopefully stop worrying about leaving the door open and risking damage by a gust of wind.

I've also painted the internal door stops. Weather permitting I'll try and get these up tomorrow.

 

[Astrokev]

Bit of a shock this afternoon when I opened the observatory to store some holly - I was greeted by a large damp patch on the floor opposite the door ?.  The patch spans both warm room and scope room, with some of the beams of the wall dividing the two rooms also being damp, as is a patch of the outer wall membrane next to the dividing wall.

I've had an initial look-see to try and figure out where the water's coming in. Three main possibilities occur to me -

1) The roof rubber membrane is leaking. This seems unlikely as the roof OSB feels fairly dry.

2) Rain is blowing under the edge of the roof above the warm-room. The rubber sheet over the beam at the top of the dividing wall is quite damp, so it's possible that water blowing under the roof is dripping down the internal face of the beam. But even if this is a problem, it's difficult to believe this would let in enough water to create the quite sizeable damp patch. The edge of the roof isn't finished yet - the gaps between the rafters are still open where they rest on the cross-beam. I intend to cover these with ply which will stop wind blowing between the rafters. I also plan to put some kind of seal between the roof cross-beam and the beam at the top of the warm-room roof. This will hopefully stop rain blowing under the roof and over the top of the wall beam.

3) Rain is channelling along the beam that supports the roof rail and is dripping inside the scope room. This seems the most likely, or at least the main source of the problem, as I noticed a large drip hanging off the edge of a piece of untrimmed EPDM at the end of the dividing beam. The flat face of the beam supporting the rail was also very wet.

So, for the moment I've decided  to leave it as is. I'm pretty busy this afternoon so don't have time to fix the root cause, but I'll certainly be pondering on the best way of blocking the channel over a mince pie or two later. I recall other folks who had similar problems with their build, so would be interested in suggestions. Making some sort of shallow barrier, like a mini-dam, feels the most obvious fix.

[Gina]

I had rain blowing into my observatory when I built it.  Mind you - that was horizontal rain!  Lots of brush type draught excluder cured it.

[Rusted]

Do not dismiss windblown rain too lightly.

Nor that a large damp patch means lots of rain.

My dome's rubber skirt hangs down below the top of the building.

The top rail still has standing water at times on the windward side in rain.

Bone dry elsewhere.

[Dr_Ju_ju]

Ouch! the uprights will be ok, but hoping that the flooring doesn't de-laminate, it shouldn't, but I've had some 'supposed' good quality go on me...

[JamesF]

Wind can drive water all over the place.  But very little water is required to make a huge damp area.

The sides of my roof come down as tight to the rails as I dare.  The membrane and cladding will drop below the tops of the walls to hide the gap.  I've also run a layer of DPC under my rails.  It overhangs the inside of the walls slightly.  When I clad the inside of the walls I'm going to bend the overlap up towards the vertical to make another barrier.

I think brush strips have got to be worth trying though.  I know some places (Screwfix?) sell ones intended for the bottoms of garage doors, so they're quite long.

James

[Gina]

I think I got 3 metre lengths.

[Yawning Angel]

In this constant drizzle, I’m seeing water tracking under the rail from the exposed side into the scope side. I’m thinking of solutions at the moment. I’m wondering if a notch under the rail at the transition might interrupt its route

Need a dry spell to investigate properly, but it’s only dripping slowly, and I’ve no floor yet. 

[Astrokev]

1 hour ago, Yawning Angel said:

In this constant drizzle, I’m seeing water tracking under the rail from the exposed side into the scope side. I’m thinking of solutions at the moment. I’m wondering if a notch under the rail at the transition might interrupt its route

Need a dry spell to investigate properly, but it’s only dripping slowly, and I’ve no floor yet. 

I think @yesyesconsidered this approach if I recall.

I certainly recognised the risk of water getting in at this part of the building when I was planning, but decided to leave thinking of the best prevention until the main building was finished. Maybe I should've thought about this earlier.

Brushes may help wind blown water, but I doubt they will stop water tracking along the beam that supports the rail, so I need to think about that one.

My EPDM goes under the rails and then overhangs the edge of the warm room roof, so that's pretty well protected. As you've found, the main problem is where the rails enter the scope room from the exposed side. I made sure the roof had a good overhang over the corners where the rails enter the scope area, so I don't think direct rain is the problem. I'm pretty sure it's water tracking along the rail beam, which acts as a gully between the edge of the warm room roof and the rail. The pic shows the affected side before the rail and roof were put on. The rail runs down the centre of the beam, creating a gully of about 10-15mm. In heavy rain, I guess there's nowhere for the water to go but into the scope room  

I've put a bucket under the corner beneath the rail and can hear dripping, so this would seem to confirm the main cause. A nice job for the new year I think. A hefty line of sealant to form a "dam" across the gully may work, or at least reduce the risk.

Edited December 23, 2018 by Astrokev

[Astrokev]

2 hours ago, Dr_Ju_ju said:

Ouch! the uprights will be ok, but hoping that the flooring doesn't de-laminate, it shouldn't, but I've had some 'supposed' good quality go on me...

?

[Yawning Angel]

It might also run under the V, if it has access. 

[Astrokev]

11 minutes ago, Yawning Angel said:

It might also run under the V, if it has access. 

D'you mean the rail?

[yesyes]

39 minutes ago, Astrokev said:

I think @yesyesconsidered this approach if I recall.

 

I did but never implemented it. I was worried bout the same thing but for some reason (not sure why) I don't get water in this way. (though it does blow in some fine snow when the weather is just "right").

I'm guessing my runners aren't perfectly straight and water runs off towards the outside.

I do have 2 of these huge paint brushes lying around that you would normally use to apply adhesive to wallpaper. Those fit into the opening perfectly. I'll use them if it ever becomes a problem.

[Yawning Angel]

5 minutes ago, Astrokev said:

D'you mean the rail?

Yes, essentially working as a pipe. Might be clear tomorrow, so I’m on for investigating 

[Astrokev]

15 minutes ago, yesyes said:

I did but never implemented it. I was worried bout the same thing but for some reason (not sure why) I don't get water in this way. (though it does blow in some fine snow when the weather is just "right").

I'm guessing my runners aren't perfectly straight and water runs off towards the outside.

I do have 2 of these huge paint brushes lying around that you would normally use to apply adhesive to wallpaper. Those fit into the opening perfectly. I'll use them if it ever becomes a problem.

thanks Chris

[nigelg]

Quote

The rail channels on my observatory have a 2" slope away from the obs. This prevents rain running into the warm room and the wind blowing the roof closed whilst in use.

Nigel

 

[Astrokev]

I've found another old image which shows the suspect area quite well. This is a view of the rail and rail support beam at the corner of the warm room where the drips are coming from. It clearly shows lots of pine-needle debris - either blown in, or brought in by the rain which may flow along the gully between rail and warm room roof. The flap of EPDM is where the water was dripping into the scope room (green arrow). I probably haven't noticed this before now, since this is the first significant rainfall we've had since the floor was put down. In an earlier post I mentioned one of my jobs was to tidy-up the internal EPDM - well, this is the bit I was referring to, as it's a bit of a mess at the moment! It was left as-was when I finished laying the EPDM on the warm room, with the intention of returning to tidy and neaten the EPDM so it doesn't hang into the obsy. One of the jobs I still haven't gotten round to.

It should be possible to construct a low retaining barrier out of EPDM and silicone between the edge of the roof and the rail, to go roughly where the red arrow is pointing. The problem is this can only be about 10mm high, otherwise it will fowl the wheel as it rolls along the rail. I'll have a closer look when it's dry and see what I can do. If this is possible, I'll probably put 2-3 barriers separated by a few inches to form a series, in case the outer one is breached.

Another thing that I think is contributing to the severity of the problem is that, at present, water runs off the scope room roof directly into the gully between the warm room roof and the rail. Another job on the list is to fit small sections of guttering at the edges of the scope room roof, to redirect the rain onto the warm-room roof instead of into the gully. I remember @Ginaused this approach and it's always been on my list, I just haven't got round to it yet. This should reduce the amount of water in the gully considerably.

Edited December 23, 2018 by Astrokev

[Dr_Ju_ju]

It's always the things added to list to do later, that can cause problems in the meantime, especially when your itching to use the Obsy for its intended purpose...

[Astrokev]

Just taken up the corner of the floor where it was wet. It's pretty much dried out since yesterday which is a good thing, but I'll leave it up now until I've finished fitting rain protection measures. My bucket had collected a fair bit of water, so it was good to have stopped this going into the ply ?.

Pleased that my design has removable floor panels, rather than them being fitted under the walls ?.