the yesyes observatory - the build

[Astrokev]

There's no food source nearby. Though I'm not entirely sure what rats consider food. ;-)

I'm not going to take this all up again now. I'll probably install some wire mesh around the warm room from the joists down to the ground. That should stop them from getting in...

To keep rats at bay (again, I personally think the risk of attracting these is very low) a mesh would probably be OK, but for mice you'll need to use a very small mesh as they can squeeze through the tiniest of holes.

[martin_h]

I have had mice in my obs warm room 3 times in the past 4 years, I still don't know how they get in. It's most disconcerting when a trap snaps shut when you are in there in the dark!

[yesyes]

The smallest (affordable one) I can find is 13mm hole size. That should even keep mice out, though I'm less worried about mice as the cats would take care of them.

This is the mesh I'm considering...

http://www.ebay.co.uk/itm/Chicken-Rabbit-Wire-Mesh-Galvanised-Netting-Fencing-10m-Roll-0-6m-Wide-13mm-Hole-/170738914342?pt=LH_DefaultDomain_3&hash=item27c0d51426

Just wondering how I would fix it at ground level. Dig it in a bit?

[r3i]

I have had mice in my obs warm room 3 times in the past 4 years, I still don't know how they get in. It's most disconcerting when a trap snaps shut when you are in there in the dark!

As the saying goes: "A mouse can get in where a draught couldn't"

[cgarry]

The smallest (affordable one) I can find is 13mm hole size. That should even keep mice out, though I'm less worried about mice as the cats would take care of them.

This is the mesh I'm considering...

http://www.ebay.co.u...=item27c0d51426

Just wondering how I would fix it at ground level. Dig it in a bit?

The rule of thumb is if you can fit a ballpoint pen through the hole then a mouse can get through! A young mouse can get through a gap as small as 6mm apparently. It looks like your cats will have some work to do.

Cheers,

Chris

[Tinker1947]

The smallest (affordable one) I can find is 13mm hole size. That should even keep mice out, though I'm less worried about mice as the cats would take care of them.

This is the mesh I'm considering...

http://www.ebay.co.u...=item27c0d51426

Just wondering how I would fix it at ground level. Dig it in a bit?

A mouse will get though a 5mm hole.

[Gina]

I've had no end of cable damage from rats And they knawed through T&G floorboards in our back porch. Any small hole where a cable goes through will also provide an "in" where they can get a purchase on the wood with their teeth. I don't think they would get through the armour on armoured underground cable though. Well I sure hope not - so far so good on that.

[Tinker1947]

We have 2 Cats live in the garden the wife feeds them but they doe'nt come inside, there's a Rat gets on the bird table feeding on the bird food,,,they just sit and watch him,,,,so don't rely on your cat he might just do the same.....

[yesyes]

on top of the possible rodent issue my tarp has ripped! we've had a downpour and it's all on one OSB sheet!

[Avo]

Personally, I'd ditch the rockwool and use kingspan / Quinntherm or equivalent.

[Gina]

I hate rockwool and will NEVER use it again! I don't care if alternatives cost more.

[yesyes]

So basically the whole problem is bad choice of insulation material? The space under the floor and the exposed insulation is not a problem but the fact that it is glass fibre insulation makes it bad?

[yesyes]

There's something else I wanted to ask.

I'm going to use UPVC cladding for the rear and side walls. Would you recommend using vapour barrier membrane on these walls as well or should I only use it for the front wall that will be clad with T&G timber?

[Earl]

So basically the whole problem is bad choice of insulation material? The space under the floor and the exposed insulation is not a problem but the fact that it is glass fibre insulation makes it bad?

Not a bad choice, it just needs to be sealed so nothing can get in and make a nice home in there

[Lonestar70]

Hi Chris,

I agree, nothing wrong with the insulation material... just need to seal it from external access by criters.

As for the Vapour barrier, yes you should use it on the PVC clad walls as well... UPVC cladding overlaps are fine for keeping water ( rain) out but not drafts, damp air and small bugs ... there will be small gaps along the overlaped faces and small insects and wind can get through... this is especially necessary if you are going to insulate the walls and add an inner skin, as it will also prevent damp air penetrating into the wall insulation... which, in turn, will result in the inside skin rotting from the insulation side.

All good fun is it not?.

Keep up the good work.

Best regards.

Sandy.

[yesyes]

more progress

On Thursday I fixed the pipe properly to the bottom of the floor joists.

And today was a rather productive day. I built 2 wall frames and cut the scope room floor boards to size.

[yesyes]

When I was almost done I noticed that I planned to put 3 uprights in each wall frame but for some reason built then with 2 only. It feels quite stable so I hope this is alright. The uprights are 75cm apart.

[r3i]

Good progress Chris - Don't know whether you feel the same but it's only when you start to put up the walls that you get an impression of how big the building is going to be.

[malc-c]

Wow, come back to this thread after a break and amazed at the progress you've made - well done

Interesting approach to building the frame, using brackets rather than screws through the timbers. I have to agree with the others regarding the rodent issue with exposed framework. I have the advantage of the brickwork to keep pests out and so far nothing more than the odd spider has been found in the scope room. If the floor frame was suspended as per your design I would of opted to completely infill the bottom of each section between the joists with thin ply, then a barrier and then the rockwool, almost the same as a normal stud wall would be between two skins. But personally having seen how rockwool soaks up moisture I would of used a styrene based insulation - but that's just my preference. This is your build and that's what makes these threads interesting as we all have different takes on construction. Only time will tell if the choice of insulation becomes a problem or not. - There is no SET way to build these things, they are all custom buildings, built to a individuals requirements and to their abilities. Like all things with this hobby, it's a case of trial and error until it clicks....

Can't wait to see how this build develops

[Lonestar70]

Hi Chris,

Looking great so far... it's starting to come together nicely now and the missing uprights should not cause you any problems, especially with all those steel angle pieces on every joint; and once all the cladding is attached the walls will be very stable... even more so, if you are planing on fitting an internal skin.

One question though... how are you planning on fitting the cladding so that it covers the centre and corner posts?

You can certainly make the cladding overlap the frames enough at each end to allow for this, BUT, how will you be able to cover the resulting cladding joints at the corners and at the rear middle upright without access? ... these will need to be sealed or you will get water ingress. I know you can get propriatory joining strips for such joints (from the cladding manufacturer/supplier) but fitting them will be a bitch on the rear centre and back corners.

Keep happy.

Best Regards.

Sandy.

[yesyes]

I decided to ignore the potential rodent and carry on with the build. If worst comes to worst, I can lift up the floor boards. They are inside the wall frames, not under.

Thanks Malcom. Regarding using bracket for the walls, I read somewhere that screwing into the endgrain doesn't hold as well as from the sides. So I thought better to use brackets. There is still a 80mm screw in each brace from the side, except for the edges of the walls where I have access. (in hindsight, I could have screwed them into the edges of the walls when I took them out again for cladding.)

Thanks Sandy. Your question will be answered in my next post (today's update) ;-)

For the join behind the middle post I bought some H-section trim. I was able to push it in from the top. I can just about reach behind that post (standing on the ground) and I was still able to nail the H-section in place. There is also ok-ish access to the left rear post. The real problem is the rear right one. I bought some plastic angle that I wanted to use to cover the corner from outside (for all 4 corners). I can nail that in place from the neighbour's garden through that trellis type fence. But today I've seen that the angle is not wide enough. So I need to order a strip of wider angle.

[yesyes]

Lots more progress today.

First I took the scope room floor boards up again and put vapour barrier underneath. I had forgotten that yesterday. Lucky I hadn't screwed them down yesterday.

There is a small gap between the boards and also between walls and boards. But it wasn't worth cutting another sheet just for a 3cm or so strip. I don't think I will feel the gaps once the carpet tiles are in.

Having the floor boards in makes for much more comfortable building when you don't need to walk around like a flamingo between the floor joists anymore.

Then I build another wall frame for the south wall.

Then I started cladding. I took out each wall frame, covered it with vapour barrier, nailed down the UPVC cladding and screwed the wall panels in place.

This shows how the cladding goes below the top of the foundations.

[yesyes]

Thanks Sandy. Your question will be answered in my next post (today's update) ;-)

Having said that... While posting today's update I noticed that I had not taken pictures of the trims after I added them. Will take some next time.

[yesyes]

Oh, I do have a picture showing the H-section from the top downwards.

[tony]

shoes need a clean

coming along nicely now.