Observatory build underway

[Tzetze]

My astronomy pursuits over the last couple of years have suffered due to having less available free time coupled with poor Irish weather. The only way to improve on this is to get an observatory constructed. I began this construction last Summer, but was delayed due to some unforeseen events. With Spring here, it's time to get things moving again.

This was the chosen site. It's in rural Ireland with a couple of nearby neighbours and, unfortunately, some recently erected streetlights outside of a neighbouring community building in view. I'm hoping the council will be accomodating here once the build is complete. However, it still has excellent views from South to the pole star and East to West.

 

Some ground clearance and a little excavation was required. So, this seemed like a good time to kickstart the long postponed plans to turn a patch of unused ground into a rear lawn with the obervatory located at the Northern end. In with the heavy machinery.

 

I decided, after reading Malc-c's build thread, to go with a wooden floor suspended from a dwarf wall and so, I was going to need to dig a small foundation. After some back breaking work and the use of a jackhammer, I managed to get this far.

 

I was close to finishing the digging out when I developed a minor illness putting me out of action for what was an unknown duration. I decided to enlist a local  builder to complete the foundation work and build up the dwarf wall. He brought along some lighter, but still heavy, machinery.

 

After 3 days, the work was done and I was left with wall, pier pipe and base.

 

Fast forward 5 or 6 months and this brings us to the present day. All the medical testing/consultations and wait for minor surgery is over. I'm now able to get back to work and so over the last couple of days, I've been back at it.

I have to install a wall plate, and went with 2x4. Outside dimensions of the wall are 5.6m x 3.1m, I used single lengths for the long side, which I bought at 5.8m

This is style of bolt I went with to anchor the plate to the wall.

 

I drilled out and countersunk holes in the 2x4 at spacings ensuring that I would get the bolts into concrete block rather than between blocks.

 

I then laid the plate out nice and square on the wall, got the corner holes drilled and held in place with dowels so that I could drill out the rest of the holes without worrying about knocking things out of square.

 

All holes drilled and the plate is now bolted in place. There was some DPC left over from the blockwork, so I put it between plate and wall. It didn't stretch all the way around, but isn't really required anyway.

 

Today, I measured and cut the floor joists. I'm using 2x6 for those and will suspend from the plate with hangers. Is it customary to rebate the plate where the hanger and nails sit, to allow the floor to sit tight to the plate?

It's great to finally be re-engaged with the build and hope to enjoy it as much as I can. I hope to get the floor installed over next weekend.

[zeroy]

Great start! Looking forward to see the progress 

[Tinker1947]

Its looking good, be nice to see it finished....

[sloz1664]

Looking good, glad you're on the mend. Onwards and upwards then   

Steve

[MarkyD]

I would have fitted the wall plates onto the inside vertical wall with stainless threaded rod and 2 pack epoxy and bolted the plates to the wall, then hung the joists from then and laid the floor boards on top of them. I did it this way for my decking. I would also removed a couple of bricks and install some vents to allow air movement under the floor to allow it to breath.

--

Mark

[laser_jock99]

Glad you're on the mend - obsy is looking like a top job.

[Tzetze]

Thanks for the good wishes all.

MarkyD, thanks for the input. I can see why you certainly had to go with side mounted plate, but I don't think I'll be choosing that option. I was aware of it at design, but I'm going to sheet the floor out on top of wall plate and fix stud walls down to timber. Didn't fancy two masonry fixes.

On the topic of vent holes, I plan to drill an array of small holes at intervals around the blockwork, that should take care of ventilation and hopefully let nothing bigger than a spider through.

[Tinker1947]

There are vent you can insert in to the vent holes, just lets air through more or less, various sizes

http://www.amazon.co.uk/Perforated-Mesh-Vents-Mini-Louvers/dp/B00AUB67TW/ref=sr_1_1?ie=UTF8&qid=1457381440&sr=8-1&keywords=Perforated+Mesh+Air+Vents+Mini+Louvers

[Tzetze]

A little update on what I managed to get done this weekend. I pulled some twin and earth and cat6 from another outbuilding to below warm room. This cabling will pass through the other outbuilding and into the main house. The flex pipe that I used for conduit runs underneath the foundation. Some of this conduit has already been buried, but I need to get this finished (can see below to left of pic) . I hope to work on this in the evenings after work this week. I ran another piece of conduit into the pier under the joists and out at around waist level. I'll pull USB and 12v through here, eventually.

And then I got the joists down. The only hitch here was realising I didn't have the correct screws for the noggins, so had to do a 30 mile round trip (Sunday) to get some. Next up is to get some insulation between the joists under warm room and get the floor down, but this will have to wait until next weekend. Here's hoping for some good weather.

[Tinker1947]

Looking nice and tidy......

[Tzetze]

Another small update. Cable is now buried from obsy to outbuilding, this cable still needs to be run into the main house. I also tacked some chicken wire to underside of joists below what will be the warm room. I will lay the insulation on this wire support before getting the floor sheets down (hopefully this weekend).

[Tzetze]

Some more pics of progress over the past couple of weeks.

We lucked out with a spell of dry weather and, with the help of a friend, I managed to get the floor down. I've put rockwool between the joists under the warm room. There is no vapour barrier under the floor sheets, but I'll put a tile backer layer on top of floor sheets and a floor covering on top of that. The tile backer will act as both a vapour barrier and another insulation layer which will help to prevent condensation underneath the OSB.

I have also drilled a series of holes in the blockwork for ventilation. Eventually, I'll cut out slots for some vent grills, but for now 4 sets of 6x 6mm holes should provide enough venting. At least, I think it should, maybe it requires more venting than this?

 

 

I cut my pier pipe down to size with an angle grinder, trying to stay as close to level as possible. A bit of sanding down later, and adapter is sitting nice and level on top.

 

I used the cut off section of pipe to mark out the hole for last remaining floor piece.

 

Then simply worked the router around it freehand.

 

It's a little rough and wobbly in places, but I plan to tack down some sort of bristle strip around the circumference to bridge the gap to the pier then cover the floor with those interlocking eva foam tiles.

 

 

I made a cut in the cut in the cut-off section of pier pipe to allow it to slide down over the pipe like a collar (can see it in above pic). This allowed me to get a water tight seal around the hole i cut in the tarp so I could get it down nice and tight to the structure - just in time before the rain and high winds set in.

 

 

Today, I got to work on cutting the uprights for the walls. 59x at 1880mm.

 

I settled on a wall height which will allow me just enough clearance to pass through the doorways without lowering my head. Here's a Sketchup of the general layout. This is looking onto the East wall. I haven't decided yet whether to drop the North wall height slightly, like in the pic, or to keep it same height all around and raise the central wall slightly higher to achieve slope on the roof over warm room. As for the sliding scope room roof, well I have a pretty good idea how I think it'll need to work, but nothing has been drawn up yet. Hopefully it'll pan out smoothly.

 

I also tinkered around with making up a jig to suspend threaded bar during pour to fill pier pipe.

I'll have to ask a neighbour to tack some weld onto those bars. I believe rebar isn't the most weld-friendly material - might have to source something else, but with some washers and nuts, this should hold things in place nicely. The central square gape should allow a decent enough pour through too.

Now, we're forecast wet weather for the remainder of this weekend and next weekend too. This will allow time to finish cutting the lengths for the walls. I might even get the lengths pre-drilled for screws if I can find the space in the shed. Here's hoping for a break in the rain soon!

[laudropb]

Coming along very nicely. Hope the weather co-operates for you.

[Tzetze]

31 minutes ago, laudropb said:

Coming along very nicely. Hope the weather co-operates for you.

Thanks, laudropb. I'm thoroughly enjoying it, never really having done anything like it before.

 

[FenlandPaul]

When we eventually move to the right house and plot, it's my dream to build my own obsy.  Reading your build updates has excited me for when that day comes!!  Looking really good and looking forward to you finishing.

Paul

[Tzetze]

Thanks Paul. I'm encouraged by your comments and have been looking forward to getting started on a build for a long time. You'll get there someday.

[Tzetze]

Hi folks. It's been some time since I posted an update but things have been ticking along nicely.

Last weekend, I got the loan of an electric mixer and got to work filling my pier pipe. I used 12 bags of sand/aggregate mix and 4 bags of cement, mixing in 3/1 bag batches. What I thought would take most of a day, was done in just a few hours. Jig and adapter template worked as well as I could have hoped. Some pics...

 

 

 

 

 

The pier has set well at this stage and any induced vibration is soaked up very quickly.  After this, any spare couple of hours was spent framing the walls.

 

This weekend, with the help of my good friend, Zeroy, we got the wall frames up.

 

And the external window installed...

Today was spent getting vapour barrier and shiplap up on the North wall...

The plan is to get the rest of the walls clad over the evenings this week. At least then, I can get the tarp over the top, if needed, before the roofing begins.

I fitted a brace to the inside of the South wall.

The top edge of South wall was leaning a little out to the East, which was kicking out of line the top rail on which the roof track will be installed. The brace has sorted this out nicely, leaving a nice straight run across the two sections for the track.

[Tzetze]

Hi guys,

Some more progress to report.

Quite slow going lately. I chose not to purchase or rent a nail gun, so ended up fixing all the shiplap lengths by pre-drilling and screwfixing.

It's time consuming and tricky work as a one man job, but it's almost there.

I painted the OSB floor with a bituminous paint which should help protect against any water damage. Floors are holding up very well so far. Some very slight rising at the seams, which is only just barely detectable underfoot. Once the floor coverings go on, I don't think this will be at all noticeable.

The shiplap worked out very nicely around the window. I chose not to install a sill for the time being. It's well sealed around the edges with silicon. I might add a wooden sill (just a ripped length of shiplap) at a later stage, but I think I'll hold off and see how the window works out as is.

Next on the list, after finishing the last few rows of shiplap, is to get started on the warm roof. Hopefully this will happen over this long weekend if the rain holds off for long enough.

Some pics...

 

 

 

 

 

 

[Physopto]

You can save a lot of trouble using no split wood screws such as "Reisser Cutter Woodscrew - 4.5 x 60mm - Pack 200" but not cheap. there are other makes Fischer being one   that do the same and cheaper.

Looks a really nice job.

Derek

[jetstream]

Very nice work Tzetze.

[Beulah]

16 hours ago, Physopto said:

You can save a lot of trouble using no split wood screws such as "Reisser Cutter Woodscrew - 4.5 x 60mm - Pack 200" but not cheap. there are other makes Fischer being one   that do the same and cheaper.

Looks a really nice job.

Derek

 

Used them last week on a project. Would be nice at £19 x 200 if the Phillips heads were not so soft! To eliminate this ... drill pilot holes in the timber...

Fabulous work, Tzetze. Enjoyed reading through this thread and love the aspect of the garden.  

 

[Physopto]

Wow! The price I saw for them was £8.80 for 200 but I thought that very expensive. I find the Fischer the best. Used them extensively,

Fischer 4.0 x 60mm Powerfast Woodscrews Zinc Yellow (Box of 200) Art. 653182

Excl. Tax: £4.61 Incl. Tax: £5.53

at http://www.fastco.co.uk/screws/powerfast-woodscrews.html?p=2

 

Derek

[Beulah]

3 minutes ago, Physopto said:

Wow! The price I saw for them was £8.80 for 200 but I thought that very expensive. I find the Fischer the best. Used them extensively,

Fischer 4.0 x 60mm Powerfast Woodscrews Zinc Yellow (Box of 200) Art. 653182

Excl. Tax: £4.61 Incl. Tax: £5.53

at http://www.fastco.co.uk/screws/powerfast-woodscrews.html?p=2

 

Derek

Wow. I got mine for a local builder's yard. (13 miles from the next nearest one, so they have the local monopoly!) 

Had to get them locally because of a project I had to finish "yesterday" and couldn't wait for the delivery man.

Thanks for the heads up.  

 

 

[Physopto]

Oooops!

 

[Tzetze]

Thank you very much guys. I'm delighted with the progress so far.

The aspect is really something, indeed, Beulah. The cost of that, though, is the howling wind that can come across those hills. This project needs to be heavy and tight!

I actually used 70mm Reissers in the framing. I was very impressed with them. Got a 650x box for €30 at my local builder supplies, which I thought was pretty good value. I went with deckscrews for the shiplap. They should stand up to the brunt of the weather pretty well.