Astrokev

So, a few pictures taken this evening. Just a few finishing touches to make to the breathable membrane, which I'll do tomorrow (thin strips around the top of the walls and a bit underneath the door). Looks a bit more like a building now, rather than a climbing frame ?. Next job is to get the cladding, but before then I've realised that it would be helpful to make the door frame to define the edges I need the cladding to but up against, so may start this tomorrow also if I have time.

Eager to restart the build after a few weeks off - this evening I put up the rest of the breathable membrane. Sorry no pictures ? Even though I still need to attach the cladding, the change in how the scope room feels when inside is quite dramatic and is re-motivating me to get moving. If the temp stays below 30' over the next week I think I'll get the cladding. Ideally I really need to finish cladding the side walls before I can finish the ROR, as to do the ROR first would hinder easy access to fix cladding to the top of the side walls. So, cladding it is then!

How did you attach your mount to the pier ? Did you have some sort of owls nest design? Of course, polar alignment can also be achieved without the need to have the top of the pier level (although having a level top is aesthetically pleasing ?).

Yes, I think that would be better - agree fully with the comments above

My question was meaning how to stop mice getting under the obsy. That's a lot of pan scourers! ?

Mesh would work fine for big critters, but I think keeping mice out (if that's what you want to do) is more of a challenge. They can get through the tiniest of holes, smaller than most small mesh sizes. I'm interested in ideas to keep these beasts at bay as they've knawed holes in the floor if my tool shed and I'd rather this not happen to my obsy when I get to this stage!

Some folks have used uPVC panels for hard to get at walls. May be worth looking into. @yesyesused this approach.

I really like the way you've staggered the joists at the corner of the frame. Looks much stronger than simply butting one side against the other as I did with mine. Wish I'd thought of that! Have you put any sort of damp proof layer between the frame joists and the concrete blocks? Without this there's a risk of moisture rising into the timber.

I've found a shiplap supplier I'm reasonably happy with. Boards seem good quality and are much cheaper than some I've looked at. The only thing that's stopping me now is the weather. From what I've read on the interweb, it's not generally good practice to put up cladding in hot and dry weather, as this risks warping, cupping and splitting. Well, it was 36'C in my back garden this afternoon, so I reckon this is a tad warm! ? So, now just waiting for it to cool off a bit before buying the cladding. For others who've used shiplap, what is the best number of nails (ribbed stainless shank) that you'd recommend I use? Net advice seems to vary between 1 and 2 nails across the width of a 134mm board (finished size). Any other tips for trouble-free installation? ?

Yes this is good stuff. My daughters landlord built a self contained flat on his land and used this. I followed the build closely and was quite impressed.

So, I'm now looking for a shiplap supplier, and what a dilemma it's proving to be. I would prefer to see the actual timber I'm buying so would like to source it locally if possible. I reckon I need around 180m and am looking at ~25 x 150 boards to make it more substantial. A recommended local timber merchant has some lovely straight and flat Cedar, which is coming in at around £670 ! Redwood is quoted at ~ £590 (and many of the boards were slightly "cupped"). Wow! This is much more than I expected! I can find cheaper quotes from more distant suppliers, but the risk there is not being able to see what I'm getting, so it may be poor quality. I'm in a bit of a quandary knowing what to do for the best....

Looking good!

Was it possibly Brookridge Timber ?

Thanks Gina, if you have the name of the company I'd be very grateful. The one I was referring to is Ruby UK based in Beaworthy. RayD found them excellent.

Still some important other things I need to work on this week, but will have time to continue work on the obsy in the free time I have. Just ordered some insect mesh to cover the ventilation holes I made in the upstand between the warm and scope rooms. I'd noticed a few wasps taking an unhealthy interest so need to get that sorted. Following the recent forum discussions, and some serious head scratching, I've done a bit of a U turn and decided to go straight for cladding and not bother with skinning the building with OSB first. I may regret this down the road, but I have to come off of the fence and make a decision. So this is the next big job. The problem now is deciding which supplier. I'm currently tempted with a supplier in Devon who offers free delivery and comes highly recommended. Recommendation is worth more than a supplier sales pitch! Need to think some more on this and then calculate how much I need. I've seen another vendor up north that supplies 3 year old larch. This has a higher guarantee that it won't warp or split but comes with a heftier price tag and is probably more than I want to spend. I just hope the weather cools down a bit soon. I'm sure the problem I'm having with my garden cabin are heat related. The temp has been over 31'C for the last few days. The cabin has been standing for 8 years now and has never shown any sign of warping until the last few weeks. It uses 28mm double T&G "logs", a few of which have warped quite badly so I can now see clear daylight between them!

Well James, you've made more progress than me in the last few days. All I managed to do was show the obsy to friends at a BBQ yesterday. Very nice to get positive feedback, but that doesn't get the thing finished! Still, I'm back on it this week between other important stuff I need to do, so hopefully a little more progress will be made. Still trying to decide what size and supplier of cladding to get. There's a place down your way in Devon that offers free delivery and comes highly recommended, so I'm tempted to use them. Recommendation is far better than going solely on supplier sales pitches!

Observatory build is having to take a backseat at the moment as I'm busy on other important stuff. The fun will hopefully resume next week ? .

Haha. It's absolutely fine Tony! I really appreciate the views of others; it's good to have discussion on this. I'm probably over-thinking it! My build ain't perfect but I'm pretty happy with it so far, and I guess I just don't want to botch it up at the final hurdle ?

Hi Tony. I note you initially agreed with Gina and Chris before editing your comment. This seemed to contradict your own comment of a few days ago - "It can be quite alarming seeing seasonal daylight appear between cladding boards or via knot holes! " and it was indeed you who suggested adding boarding underneath the cladding ?

Thanks Chris and Gina, I really appreciate your input on this. I guess I'm still pondering. As I see it, whether I add OSB or not, if the cladding doesn't shrink then the end result is the same, except that I have a more secure building by using OSB ? Whereas, if the cladding does shrink, if I've used OSB then everything is fine, but if I don't use OSB then I have a problem that is really difficult to rectify. Vapour membrane would stop water getting in, but I don't really want this to be the defence from a security viewpoint. Regarding getting good quality cladding, I'm not convinced this is simple and guaranteed, and may be more of a lottery. My garden cabin has double T&G timber "logs" over 2 inches thick (much thicker than shiplap), cost a fortune, and has been absolutely fine for over 5 years. Last week I noticed a few of the timbers had pulled apart and I can see fresh air through the gap. I can only think this is due to the prolonged heatwave. So, although adding OSB would add a bit more cost and time, in the grand scheme of things this isn't a problem for the added reassurance it would give, together with the extra security. I've been building the obsy for a year now, off and on, so a few extra days/weeks and a bit more work are not really a problem. But.... I'll think some more on this and price up the added cost of using OSB.

So, I've now realised my first major design flaw of the build..... I say major as I'm sure I've made loads of minor ones! I originally didn't intend to put sheet material on the outside of the walls, just cladding. Therefore, I intentionally designed the wall studding to be less than the more conventional 400mm centres to give it more strength. This is fine except that the studs now don't fall conveniently to allow me to use full sheets, without adding more stud work. I'll have to cut the sheets to suit, which will be more wasteful and time consuming. Oh well, lets hope this is the only significant design flaw! The other thing I would have done differently is to inset the wall studding from the edges of the floor to allow room for the OSB sheets. This isn't a major problem, I just would have done it differently had I considered this approach when I designed the obsy! Onwards and upwards ?

Yes, the FH Brundle wheels and track are amazing!

Not much progress on the build today. For one thing I was at a family BBQ enjoying some social time. The other reason was it was just too hot. Electronic temp sensor was reading 33.9'C in the shade this afternoon, and it felt it! Phew! This evening I did manage an hour though. I stuck down the edges of the EPDM to the side of the track rail with contact adhesive. I can now trim this which will enable me to make the catchment structure and check for clearance along the entire length of roof travel. The other big news is that I've now decided to put an OSB skin on the outside walls and then put cladding on top of this. This will make the building much more secure and will remove any risk of gaps caused by shrinkage of the cladding. The downside is I'm going to have to remove the breathable membrane I'd already put up, as this needs to go on the outside of the OSB. Started this this evening; a slow job trying to remove the clout nails without damaging the membrane, but well worth it.

Looking really good James. I like the fact that you're fixing the wall frames directly to the joists, and not through the floor boarding. This is similar to my build and means any future issues or changes you want to make to the floor can be dealt with without taking the walls down! A much more flexible approach.

OK, so off came the rafters and noggins, ridge beam and N & S beams cut back by 17mm, rafters and noggins put back on. I'm now back to where I was at 9.00 this morning - except that the capture structure should be a much better fit ? . Following the suggestion by @nightvision I'm now pondering on whether to skin the obsy in ply or OSB before I put on the cladding. Much as though I'd like to get the OSB and EPDM on the rolling roof, it will probably be easier if I can clad the gable ends first, so this is now top of the priority list....