Obsy floor, wood or concrete?

[Odd Thomas]

I know there are pros and cons for each, but I'm looking for input from those that are lucky enough to have their own observatory, regarding a wooden floating floor v a solid concrete slab. The pier will be isolated from either so this is not an issue. Have you laid a concrete floor and wished you'd made it wooden or vice versa? Access is reasonable for either so that is not an issue. any thoughts would be appreciated. Thank you.

[malc-c]

My build uses a suspended floor using traditional joist hangers and 18mm ply.  The pillar was concreted into a big hole in the ground and the floor doesn't make contact with the pier as it has a 4mm air gap around it.

As the brickwork has a DCM  the floor remains warm and dry.  Solid concrete will be cold on the feet if you intend to spend your time in there whilst observing or imaging

[DaveS]

My obsy has a concrete floor (The top of the massive foundation block), but as I image remotely it's not usually a problem. One thing though, if you do go for a concrete floor get some rubber tile matting otherwise you WILL drop something expensive with a horrible crunching sound. In my case it was my mobile phone which I was using as a clinometer.

[Odd Thomas]

One for each. 

malc c, is the grey material insulation under the floor?

DaveS, thats a good point.

I hadn't thought of the cold issue, something to take into consideration definately.

[malc-c]

11 minutes ago, Odd Thomas said:

One for each. 

malc c, is the grey material insulation under the floor?

 

Yes,  Like Dave I now image remotely, so its less of an issue.  But originally I used to spend the nights in the observatory whilst imaging.  The observatory is 4.8m x 2.1m and split into a scope room and a "warm" room.  The warm room has 50mm insulation under the floor, and 30mm in the walls and roof.  The scope room has no insulation at all so it is more or less the same ambient temperature as the outside air.

The floor is 18mm external marine grade ply, and like Dave, in the scope room is covered with foam matting which has saved the odd eyepiece / camera over the years.

[pmlogg]

I used decking on mine with no insulation underneath.  It never feels cold underfoot; a completely different experience from concrete.

[mikeDnight]

Mine has a floating wooden floor made from 3/4" ply screwed to 6" joist's. There's no underfloor insulation but the floor is covered with black interlocking rubber exercise matting, which is acts as a protective insulating layer. The floor has a 1cm gap around the pier, but the rubber matting butts upto the pier closing the gap. There is no vibration from the floor transferred to the pier. After 11 years of use I couldn't be happier!

[Yawning Angel]

Another floating wood vote. Polystyrene insulation between the joists, vapor barrier and 18mm ply on top. Interlocking gym floor tiles over that. Warm and dry 👍

With a suspended floor, you might want to fix mesh to the perimeter, to stop small creatures chewing insulation / cables underneath. 

[Odd Thomas]

All good info for a first time builder, thank you. Taking on board the above, I'm leaning towards a suspended wooden floor.

We have the planning permission from the council through now, and I'm hoping to start the build around May. No doubt I'll have the usual questions for you all.....

[malc-c]

Just spend a few hours (days?) reading through all the previous build threads and pick out parts that you want to use in your own build.  I took inspiration form a couple of SGL members, but merged in the dwarf wall to suit my own needs.

[Odd Thomas]

malc-c,  yes you can easily loose an hour or two doing that!

If I go the route of a wooden floor, I may well land it on a dwarf wall. The field where its going is on sloping ground and can get a bit squelchy in the wet.

[Swoop1]

And don't forget- a thread about an new obsy is useless without pictures.