Gina's Observatory

[nightvision]

.... duplicate post!

[malc-c]

That ship lap is good value for money, and based on that price I could of saved myself around £130. But then again I've gone for thicker 19mm boards that are around £8 a length (5.1m), so I guess that's why.

Those runners work out more than the 50 x 150mm joist I purchased from Lawson's so I would suggest 146mm x 45mm (6inch x 2inch) PAR (planed all round) Redwood Timber - Pine (Skirtings etc) - Timber - Timber & Sheet Materials which might be cheaper (OK its not pressure treated... but soak them in creosote for a couple of days that should do the trick )

I would suggest you drop Helen a PM with the link to Savoy's website as a source / resource for materials

[astroimpulse]

I've just perved the life out of that site and their prices seem great. I've not gone and compared anywhere else but their decking seems decent.

[Gina]

Rain stops play!! Made an early start on excavating but it's started raining now Think it's only a shower though.

Calculation of timber requirements is progressing and it certainly looks like exceeding the £300 free delivery threshold.

I'm looking at several changes in the design as a result of longer timber length being available and my decision to go with OSB + felt for the roofing. I have changed my mind on the studding - I'm going for larger timber but fewer studs. 3x2 (75x47mm) with 4 uprights for external obs walls and 3 per warm room side wall, 4 for the end wall, not sure about dividing wall.

Using felt for roofing means less slope and makes sloping towards the warm room feasible again. This means rainwater can run off the obs roof onto the warm room roof and into one piece of guttering on the warm room end wall. Allowing for 6ft at the low end results in about 7'6" at the highest (obs east end). This gives more headroom for scopes allowing a slightly higher pier and higher walls, reducing the weight of the roll off section.

The running track supporting timber can now be a single length of 3x2 and supported at the outer end from the warm room wall. At the same time the warm room will be wider - something like 7ft. Extra room is always welcome. Little extra cost would be involved if any. The less complicated construction and less guttering would well compensate for the extra materials used in the warm room.

I'll post drawing of my new design shortly.

[Astrokev]

Still excavating?!

[Gina]

On and off... Not been able to do much lately due to the weather If the weather lets up I could finish that part today.

[Gina]

Here are the latest rough design drawings.

1. Floor beams, joists and plywood. (7"x3", 4"x2", 8'x4'x12mm)

2. Base plan - floor level and above

3. South elevation

4. Roof join detail showing shaped aluminium plate to direct rainwater from edges of obs roof into warm roof area.

[JKB]

Hi Gina

Have you tried Victoria Sawmills in Devon? I have used them before and very competitive.

All coming along nicely I see

Jamie

[nightvision]

Great evolving design, some real improvements. Is there a door between the warm room and obs? If so watch the obs roof end-panel doesn't obstruct it, or you could have it open into the warm room, however I can't tell the height of the obs walls from the diagrams so might not be an issue.

[Gina]

Hi Gina

Have you tried Victoria Sawmills in Devon? I have used them before and very competitive.

All coming along nicely I see

Jamie

I'll check them out. Thank you

[Gina]

Great evolving design, some real improvements. Is there a door between the warm room and obs? If so watch the obs roof end-panel doesn't obstruct it, or you could have it open into the warm room, however I can't tell the height of the obs walls from the diagrams so might not be an issue.

Yes, I am having a door between obs and warm room, either opening into the warm room or sliding. I'll add dimensions to the drawings and post them shortly. I can see that the info is incomplete without dimensions.

[Gina]

Having decided not to buy any timber (or roofing felt) from Wickes, I have now put in my order for the cement, ballast and guttering. I expect to order the timber in the next few days.

[Macavity]

Just bought a couple of sliding door kits. One for obsy, one for the (house) Loo! Have a slight circumspection re. sliding doors, ever since watching the "Texas Chain Saw Massacre". LOL. However:

http://www.stormguard.co.uk/pdf/SlidingDoorGear/DoorGear.pdf (Via many suppliers)

Envisage making my own doors with Aluminium U-channel and wood offcuts?

[Astrokev]

Here are the latest rough design drawings.

1. Floor beams, joists and plywood. (7"x3", 4"x2", 8'x4'x12mm)

2. Base plan - floor level and above

3. South elevation

4. Roof join detail showing shaped aluminium plate to direct rainwater from edges of obs roof into warm roof area.

Interesting. Buy some wood, quick, before the design changes again!

[malc-c]

Gina,

If I understand the drawing correctly, you are going for a suspended floor based on 4" x 2" joists suspended between three 7" x 3", one at either end and one mid way at the 8" mark. If so I have my reservations as 4" x 2" would not be substantial enough to provide a floor that wouldn't bounce or move. IMO you would be better off making the complete frame, joists and noggins out of 6" x 2", spaced at 16" centres. Oh and 18mm should be used for flooring... IMO

[Astrokev]

Gina,

If I understand the drawing correctly, you are going for a suspended floor based on 4" x 2" joists suspended between three 7" x 3", one at either end and one mid way at the 8" mark. If so I have my reservations as 4" x 2" would not be substantial enough to provide a floor that wouldn't bounce or move. IMO you would be better off making the complete frame, joists and noggins out of 6" x 2", spaced at 16" centres. Oh and 18mm should be used for flooring... IMO

Hi Malcolm

I used 12mm ex ply for a shed floor recently, and it is very firm. I think it depends on what centres Gina uses. Any wider than what you suggest and I'd agree that 12mm is a tad thin.

I've no current experience of shed joist thickness, but based on DIY decking I'd agree that 4" does feel on the light side.

regards

[Gina]

The joists are at 16" centres except the outer ones which are about half that. The sheds I've seen used 4x2 joists at that or wider spacing but admittedly sheds tend to be made as light as possible. I agree that 4x2 would be a bit light for decking where you would expect several people standing in a small area. It will be just me in the obs and warm room or me +1 at most.

I could move the middle beam to the actual middle at 7ft. The partition wall takes no weight other than it's own - the roof structures bear on the side walls.

[Gina]

According to the floor loading tables Load-Bearing Walls And Safe Floor Joist Spans

97x47 joists at 400mm should be supported at 1.92m so I'm just a bit light. 7ft is 2.13m.

[Astrokev]

Fair enough Gina. As I said in an earlier post - it's YOU that you have to satisfy, no one else!

Looking forward to seeing your build start soon. This is turning into the longest thread on the forum!

[Gina]

5x2 alias 122x47 would fully comply with recommended loading

47 x 122 mm 2.55 m

I'll see if they do that size and at what extra cost.

[Astrokev]

5x2 alias 122x47 would fully comply with recommended loading I'll see if they do that size and at what extra cost.

see previous post!

[malc-c]

Have to agree with Kev, at the end of the day its your project, and it's down to you how you build it and out of what materials. We all have different opinions and standards that we feel are right. - If you are happy with using 4 x 2's at 400mm centres then that's OK. Some may say that I've gone overboard using 6 x 2 joists with 18mm exterior hardwood ply for the floor, but it's solid and I'm comfortable that it will support however many people may cram in to the observatory if I ever hold a party and people want to see the scope in action.

My only comment is, and I'm not wishing to offend, that you keep on changing the plans and going over ever area of the design in fine detail, which is fine, but will lead to delays in getting started, and you end up going round in circles. Trust me your best laid plans will go out of the window as you build the thing, often something pops up and you have to work out a resolution as you go.

[Astrokev]

Well said, that man!

[Gina]

I guess I do have a penchant for changing my mind And yes, I expect a few details will change as I build. Anyway, I'm freezing my design in the main and basing my timber order on the current version (unless someone comes up with a problem with it). I'll post dimensions for everyone's perusal - I may have missed something stupid.

[Gina]

I think I've dug deep enough for the pier base now. It's 18" below the bottom of the joists, 24" wide and over 48" long depending on how far I take it. The ground is heavy clay and stones, very firm and hard. It needs a bit more depth for concrete under some of the beam ends (the ground slopes) but nearly there. We have had a lot of showers today so haven't been able to do much outdoors.