a cornish obsy build

[Gina]

I'm afraid I have to agree with Malcolm.

[Astrokev]

Yep, me too. May work, but just seems an awkward and illogical way of designing your base. Sorry! Still time to consider redesign though

[tony]

I can see where you are coming from and i thank you all for your comments. Ok, so

Lets just assume i havent started yet, and lets also assume i will be building my shed on to block piers, one on each corner and one each along the front and rear, and then build my 6x2 floor frame on top of that, get my drift.

[tony]

I guess not.

I am at work atm on nightshift but when i get the time later i will post a more detailed description. But i'll try and answer a few queries.

Astro kev and nytecam, nothing will be attached to the rear garden wall, its not all that great tbh. And where i say pier i'm not refering to a scope pier.

Malc, i dont think you fully understand, if i were to remove the blockwork completely and support the frame on the four corners instead i'd need some support in the centre front and rear, so i see no difference in just having the support in the centre at the rear, it doesnt need the support along the full length, the rear isnt visable so i'm not too bothered about it thus saving me having to dig a trench and fill with concrete then lay block.

Edited April 23, 2013 by tony

[tony]

You don't need more founds - use joist-hangers off the old wall - oh my giddy aunt

fpmsl, i havent heard that for ages.

[tony]

right, am home from work so a quick play with sketchup to give an alternative floor frame/blockwork layout.

if i remove the dwarf walls i need to support the 6x2 frame by way of a pier/support (or a concrete block) in each corner and one each along the rear and front.

but i am not using piers to support my floor, i have built 3 walls, i see no need for one at the rear, and as stated earlier by building a block pier i have saved time by not having to dig a whole trench to fill with concrete then build a wall on it.

the reason for not using 6x2 all round is i need to keep my overall height at 2.5m max, my walls will be 1800, by the time i add the roof it'll be about another 200 approx, add to that the 150 floor,plus my blockwork at the lefthand end being 450 bringing me in at 2.6, by using a 4x2 wall plate i have reduced my height by 100mm bringing me in at 2.5m which is where i need to be.

onto the floor itself, 6x2 along the rear, with 7 6x2 joists spread along at 450mm 900mm 1350mm 1800mm 2250mm 2700mm and 3150mm , fixed in place by way of joist hangers. at no point am i attatching anything to the garden wall behind, its Rubbish tbh.

i dont think i can make it any more simpler to explain other than it'll more than be strong enough to support what will eventually be built on it.

[tony]

am off to bed, its been a long night.

i dont want to seem to critisize anyone, afterall this is a build thread and i am open to any sugestions/criticisms along the way that could/would help me and for that matter anyone reading this and wanting to build their own obsy.

i will let you read the last few posts above and have a think about what i've said and i will post a pic here later, taken from what i consider to be the best obsy build on this site, i watched this particular build from start to finish and was really impressed, my floor design is partly based on that persons floor.

if you have time go and have a closer look around the different builds,you will be surprised at what you will find.

[Astrokev]

Hi Tony

Like you, the rest of us are avid build-watchers (and some are avid builders - I'm still gearing up to start my own build this year ), so I'm sure we are all very aware of the range of designs, and the ups and downs, of the whole process. Not sure who's build you are specifically referring to but I, and everyone else, probably followed this post-by-post like you.

Your latest pics show an effective and alternative way of constructing a base, which has been used by some others to produce an excellent end result. The choice is therefore yours; a choice that is influenced by many factors, and often includes a degree of compromise along the way. There are many ways to skin a cat, as they say, and such is the case with obsy design.

My personal reason for trying to offer constructive criticism was that your design seemed to be a mix of 2 methods, either of which would work on their own, but I couldn't (and can't) understand why you chose to mix the two!

As you've pointed out, this forum is a great place to share ideas, to learn from others, and to continue to build on our collective experience. It's also a place to take on board and consider thoughts and points of view that may be different to our own. These thoughts are offerred with the best intent - ie. to help you end up with a great observatory, and are not public floggings!

May I suggest you read (if you haven't already) Gina's build thread (I should book a day off work first!). Her design changed many, many times based on discussions that lasted for over 2000 posts, and it was fantastic to see the thoughts and evolution of her obsy develop. The end result was a great observatory that she's very happy with.

Finally, and back to your own build, I personally wouldn't consider knocking the walls down and starting again with design #2. You've put too much work in for that. I'd either just build a 4th block wall, or stick with your original plan. This will work as I've said, it's just a different way of doing things.

Looking forward to seeing the rest of the build.

Oh - and a question - your height limit of 2.5m. I presume this is based on building regs? With such a heavy ground slope, where are you measuring the height from, ie. the high or low end?? Just curious.

Kev

[Gina]

Thank you for your kind words Kev You are right

May I add another point? With vermin and other wildlife proof front and side walls you have good access for wildlife at the back where you seemingly can't get at. You are building a wonderful virtually draght proof nest for for anything that feels like using it. TBH this is not a good idea. Either an open well ventillated gap between floor and ground or a vermin proof structure on all four sides with air bricks for ventillation. With an open space cats can get in easily and stop vermin and the place is far less cosy and encouraging. Since you already have three walls built with all that effort, I would advise a fourth wall with air bricks though the present air bricks may well be sufficient.

Edited April 23, 2013 by Gina

[malc-c]

I have to echo Kevs comments. Whilst we can all chip in with comments, some based on our own experience having gone through the process of building an observatory, this is your build and its up to you if you wish to take the comments on board or follow your own design. Every build gets modified as it progresses. Sometimes this is due to a problem that arises in construction where you see a better way of doing something, or because something gets overlooked due to lack of experience (as I did with the lack of air bricks in my enclosed wall design).

Personally, as Kev mentioned, you have done such an excellent job of the block wall it would be a shame to knock it down. Also for the reason stated by Gina, a raised platform, or one with access at the rear could lead to issues with rats etc. The consensus from the members here would be to continue with the block wall all the way round. This will provide a very sturdy base on which to build the rest of the observatory, and for me seeing what you've done so far and what you intend would be a backward step. But this is just my opinion, and that's what public forums are for, voicing ones opinions. At the end of the day it is your build, and there is no rule book of what is right or wrong (many ways to skin a cat as Kev puts it) and it's this variety of builds that make DIY observatories so interesting to follow as we all learn and pick up things we either missed or could incorporate in our own projects.

[tony]

thanks guys, comments received and welcomed, not a problem there at all, and i thankyou,but i think we've missed the point here.

the question was asked "what is supporting the rear wall" am icorrect? and that why i've cut a corner not building the 4th wall, and two other members backing up that question.

i have tried explaining how this will be done by way of an attempted google sketch thingy lol. and further saying that it does not need support along the full length (3.6m).

yes i',ve cut a corner, for a good reason, it saves me time, i see no reason to build a wall there, and as for vermin getting in, when its finished there will be mesh behind there so no problems, and besides there are plenty of builds that leave all 4 sides open. at my old address i had a similar shed base (24x8) built in the same way but with 3 piers along the rear for support, no vermin and structurally sound and never moved an inch in 14 years, so from my ppoint of view i am using a base that for me is tried and tested.

astro kev, i'm not knocking down the base and making as the 2nd drawing, that drawing is merely showing the same size frame but done without walls all the way around and the front and sides as 6x2 supported on all 4 corners and the centre front and rear, whereas mine is the same size frame built on 3 walls but the front and sides replaced with a 4x2 wall plate.

i'm not having a go here, just trying to get my point across.

so i suppose that if my method seems illogical, then why oh why oh why does near enough every single build thread have everyones floor frames built onto partially supported bases not onto 100% supporting walls (as in malcs) but instead supported in only a few places. malcs is by far the stronger base here, 100% cant beat that. so i fail to understand why my floor frame, which is probably about 70% supported questioned? i am just pointing out the way in which it is to be built and as i have said it does not need to be supported along the full length.

onto the thread i mentioned where i sort of pinched the idea of a 6x2 floor frame( fairly similar to my 2nd google sketch)

here it is,

are you going to tell him that his floor is not strong enough?

this to me is the best one i've seen, aoraki

Edited April 23, 2013 by tony

[tony]

take away the front and sides of aorakis frame and replace with a 4x2 wall plate, remove the 4 corner and centre front concrete blocks and replace with 3 walls and sit the frame onto the 3 walls.

i hope it makes sense now.

[dmahon]

I think it's a fine idea. After going to all the effort I would personally have built walls all around, but tbh I wouldn't have gone to the effort in the first place and would have just used supports at the corner, as above plus as necessary according to span tables. But as you're low off the ground (so it's easy) I'd probably add a few vertical 4x4s here and there to the beams and the joists too (but wouldn't bother with concrete pads underneath, nor sink them into the ground)

Using walls on the visible sides for cosmetic reasons only is perfectly valid.

[malc-c]

Tony,

Your post come over as somewhat defensive as if we had offended you in some way, which is not our intention

Agreed, aoraki's build is probably one of the best in terms of engineering and in looks with the additional decking area. Supporting the floor frame work on blocks is an option, and there was one build thread where the frame was supported on a grid of blocks but spaced closer than just one at each corner and one in the centre. It will work and Aoraki's thread proves that. I think what was confusing people was we were all expecting you to follow the traditional format of a dwarf wall all round and felt that you were compromising by spanning the back and supporting it on a block pier, mainly in a bid t save some time and effort and probably a little cash too . Like I said in my post above, this is your project and you can build this as you see fit.

With regards to enclosing the structure, you'll also notice that Aoraki's build also included a complete boarding down to ground level, something I would suggest you consider

As I stressed in my post above, this is a public forum and you'll get peoples opinions on how they would / have done things. Some comments will be favorable and others critical. Bottom line is it's your time, money and effort and you can do whatever you feel fit... Its YOUR project and only you will be using it. There is no golden rule of what method is right

Edited April 23, 2013 by malc-c

[tony]

Using walls on the visible sides for cosmetic reasons only is perfectly valid.

thankyou.

[tony]

malc,

if i came over as defensive i apologise but i felt it the only way to get my point across.

i'm not offended and i hope no-one else is.

[tony]

Tony,

I think what was confusing people was we were all expecting you to follow the traditional format of a dwarf wall all round and felt that you were compromising by spanning the back and supporting it on a block pier, mainly in a bid t save some time and effort and probably a little cash too .

thats the impression i got malc, people getting confused with what is actually happening here, and also trying to get my point cross by way of some dodgy google sketchup pics lol.

[tony]

Oh - and a question - your height limit of 2.5m. I presume this is based on building regs? With such a heavy ground slope, where are you measuring the height from, ie. the high or low end?? Just curious.

Kev

the high end. regs do state 2.5m max from original ground level, the blockwork is already 450mm.

as i'm within 2m from the boundry i only have a 2.5m max height.

Edited April 23, 2013 by tony

[Astrokev]

malc,

if i came over as defensive i apologise but i felt it the only way to get my point across.

i'm not offended and i hope no-one else is.

Not offended, but a little surprised at the, as malc delicately put it, 'defensive' response! Having just quickly checked, I appreciate you've never requested opinions of others, but as a number of us have said, in a public forum folks will offer opinions, thoughts, comments. Isn't this why we post these interesting threads that we all love to follow and engage with? Maybe you just want to use the forum as a shop window to show what you've done, without engaging.

Regarding your answer above - "then why oh why oh why does near enough every single build thread have everyones floor frames built onto partially supported bases not onto 100% supporting walls".

A valid and true point, but I can't remember seeing too many builds that were a mix of the 2 approaches, which was the point that was being made. Both methods work fine, and mixing the 2 will work fine, it just seemed an unusual way of doing it, which was the point I was making. No big deal.

Looking forward to seeing the rest of your build.

[tony]

Perhaps i may have taken some comments as being too critical and questionable, if i have misunderstood those then i apologise.

And to a certain degree i can also see your point of mixing the two approaches. For me it makes sense, for others it will and may seem a bit odd as to why.

As malc has said there is no golden rule and everyone will have their own ideas to put forward, and any comments and suggestions are welcome, but if i feel that those comments are questioning what it is i am doing then i feel i need to answer those questions, and if it seems that i am defensive then again i apologise.

I do hope that i get the benefit of the doubt when this build is finished and you will appreciate the way in which certain things are done, i have spent many hours looking at the builds, not just on here but on the www and some i have seen are questionable but all to their own as they say.

Lord knows what you'll think of my roof, ( intended as a joke there) i've mulled over so many different options that it hurt my head lol.

[Astrokev]

I'm sure your roof will be fine!

Obsy design ain't easy. If I had a pound for every idea I've binned for my own obsy designs, I could retire tomorrow.

[tony]

Likewise kev.

[Gina]

I accept your appology - thank you

Pretty well everyone knows how long I took mulling over designs before I even got started then as the (slow) build progressed things got changed as I got experience and read the opinions and advice of other members (which I greatly appreciated, I have to say). SGL seems to be a bit different from some other message boards - I've haven't seen any nastiness or destructive criticism on here whatsoever - we love to help others and stop them from doing things they might later regret but as Malcolm says we are by no means dictating - just trying to help in what is a very difficult area and where things can go seriously wrong. The written/typed word can so easily be misconstrued without the body language to add to it.

Good luck with you build - we all look forward to your posts and seeing how you do

Edited April 24, 2013 by Gina

[r3i]

The written/typed word can so easily be misconstrued without the body language to add to it.

That is so true - sometimes I just can't get the words together to say what I mean.

Keep up the good work Tony, take your time and enjoy the bulding process as much as the end result.

[tony]

The written/typed word can so easily be misconstrued without the body language to add to it.

That is so true - sometimes I just can't get the words together to say what I mean.

thanks gina, mike.

i've just sat here and read through the whole thread, as if i were someone else looking in so to speak, and can see now where things got misinterpreted.

it does look as if the rear garden wall is part of the obs and i clearly got the wrong end of the stick when questions were asked and for that i'm sorry, you can slap me later

as you say mike,sometimes people just can't get the right words together to say what they mean, and perhaps i got a bit frustrated when they were as gina says misconstrued without the body language to add to it.

off on hols in 2weeks time and have a few other jobs indoors to do still so i doubt a lot will get done till then.

timber will be ordered hopefully to get delivered before i go away but i'm undecided whether to go for loglap or shiplap. £53 difference in the price

Edited April 24, 2013 by tony