|
Post by cannyfradock on Jun 13, 2012 17:16:26 GMT
Nice touch.....I think arches fit in anywhere....the more the merrier. Not quite sure how you are going to work it into your BBQ.......?
Looking forward to the next stage......
Terry
|
|
|
Post by umhloti on Jun 13, 2012 22:11:36 GMT
Terry it will be a dome .and then another one on top of the dome . You will see when its finished . Something different but i cant take the credit for it as i saw it somewhere else before and thought it was brilliant.Three bricks deep Attachments:
|
|
|
Post by turkey on Jun 14, 2012 8:26:47 GMT
so it is going to be like an Argentinean grill, suspended from the vault? You could even get dome sort of chimney in there also?
|
|
|
Post by umhloti on Jun 14, 2012 8:41:46 GMT
yes almost . Well it will be dome looking but suppose they are arches so more of a barrel pizza oven on steroids with the front cut off ;D
The chimney will be a flu on the top . I have a flu pipe and hope it works as it will be in the middle of the arch where the keystone will be . This is a concern for me as all pressure and strength of the arch will be there !!!!!
Was wondering if anybody knows when is a good time to take the template off re the arch as i used cement fondu. I know its quick setting and strengh quicks in after 6 hours and then 24 hours . those are the test figures 6 and 24 but those are labs and dont want to do it again so would be open to some good advise ?. its been 12 hrs now Thanx
|
|
|
Post by umhloti on Jun 14, 2012 9:48:54 GMT
just took it off after 12 +hrs couldnt wait. But seamed a little bit rockey dont know what to do to start from scrath or carry on as this will be joined to 2 other and then another layer of bricks over the existing arch which would strengthen it Attachments:
|
|
|
Post by umhloti on Jun 14, 2012 11:27:44 GMT
took the arch down decided to start again in a few days . The bits that took where very strong and bonded well together. I have been trying to seperate some of the bricks and even a lump hammer is not doing much damage to it .Realized what was one of the big contribution factors to my failure. Because the span of the arch is 140 cm its rather big the template and because i am very exposed to wind it acts as a sail and must have been shaking all night which is disastrous when trying to set cement concrete . So nxt week after this bad weather will start again and build al 3 arches that makes up the dome or barrel in one go . make some holes in form to let air/wind through as not to shake form so much and maybe with all the weight of all 72 bricks it will be better prepared for the wind. Have to choose one morning early with no wind and do it all in one go .
|
|
|
Post by turkey on Jun 14, 2012 13:52:12 GMT
thats a shame, although if it stood up with only some parts of it properly set and fixed then that shows that with 3 rings properly set it should be very sturdy indeed.
I dont think you need to worry about the flue being in the middle unless you remove all the keystones, in most of the pompeii builds the arch is cut in the middle for a flue and they all stand up ok. If the arch is quite deep then there will be hardly any keystone missing compared to the percent still left so will be even less of a concern.
|
|
|
Post by umhloti on Jun 14, 2012 14:25:36 GMT
Yes it was sad to break it down . Suppose i was trying to save cost by only buying one sheet of ply to make the template . Ye it should be very strong when all in place.
The flue will act as a type of a key stone in the middle of either sides of the bricks from 4 sides and then wil be wedged in with the final keystone in the front that will form one of the 4 sides of the flue from the front view.
The wind i think will be my only enemy then till it sets and cures . Have to choose a good day early morning 4am or so to get cracking.
|
|
|
Post by turkey on Jun 14, 2012 15:49:32 GMT
can you errect some sort of wind break? put some old beach wind break to good use?
or just pile up some of the un-used bricks to make a wall for horizontal movement support?
I took Terrys lead and spent a little extra and used celotex insulation for the form, I think it was a fiver but its very easy to cut with a knive / saw and is 5cm thick so the bricks stay on it very nicely. The main rason is that I hate my jigsaw as the blade always jumps the guide and cuts at an angle. I thought it would be easier but as it turns out my eye is just as wonky as the jigsaw and it needed some tweaking after the cut lol.
|
|
|
Post by umhloti on Jun 14, 2012 16:18:57 GMT
No shelter would be hard . Its so exposed here and winds so strong that garden sheds blow away here. The top of the arch is around eight foot.
Somedays its so windy its almost imposible to get out of the car
I dont know how iam going to do this but will make a plan.
Thanx Turkey is celotex is a very good idea
|
|
|
Post by cannyfradock on Jun 14, 2012 18:09:52 GMT
Umhloti
Is that the first arch of your barrel/Vault build?......If so, then you need to build your rear wall first and start from the back and work your way to the front. This will give your first arch the stability it needs. If you are building arch on arch then you need to butruss the base of the lower arch......or build a single brick pillar either side of the base of the lower arch. (the stresses of an arch go from the top of the arch in a downwards direction to 20 past and 20 to (if the top of the arch is 12 o clock)
I still can't understand the reason for building a single arch......please enlighten me if i have misunderstood what you are trying to achieve.
As for the time needed before removing the forms.....I would recommend 24 hrs.(I remove the forms 4/5 hours after the keystone has been laid, arched.....or dome forms).....24 hrs and the bricks and mortar will be set. (the mortar only starts curing after 7 days)....always try to use folding wedges under the forms, so as when you remove the forms, you can lower them down. That way the forms won't catch on the fresh brickwork.
Terry
|
|
|
Post by umhloti on Jun 14, 2012 19:05:21 GMT
Terry
No its going to be 3 arches when completed . Just like a barrel pizza oven 3 deep but with the front cut off so that you can see the BBQ so 3 bricks deep. i did the first arch but should have done all 3 in one go . That was my mistake i think . The strenght whould have been there if all in one go .
Yes I used pieces of wedging but was batteling i think due to the weight to get it out . I dont think that was to much rocking from that . And it was cement fondu after 12 hours. The sections came apart in 3s 4s and 5 and think 6 but the pieces were solid in the groups . it just had 3 or 4 weak points. Heart breaking.
I think next time round i might use car jacks to lower forms when dry and this will be more smoother I think?
|
|
|
Post by cannyfradock on Jun 14, 2012 19:53:16 GMT
Umhloti ....Apologies....I still can't get with the program. 3 brick deep vault...ok, but that seems far to much width for the depth. I'm sure that when I see your next set of pictures I will understand your design. .....a couple of points...I've never built a Vault oven, but the people who do.....usually build 3, 4 or 5 courses of brick on either side....THEN, create their vault arches on top of this. The curveture of the arch will then be a lot shallower, but as long as the arch is part of a perfect circle (or conforms to pi) ....it doesn't matter how shallow it is. Just make sure the internal height of the arch is no more than half the width of the oven. By building a couple of straight courses on either side will bring the width in making it easier to form the arch transition ?? Constructive critisism......there is far too much mortar in between the inner side of the arched bricks. When looking at the underside of an arch there will be only millimeters between the bricks, and each perp should be wedge shaped. You can always mark the bricks on your form...then follow your marks. Start from either side and if it doesn't work perfectly then cut the last brick....or cut the last 2 bricks (don't lay a brick flat to make up a gap.....lay them all "on edge". My brickwork isn't perfect, but have a look at my arches to give you a guide on what I've said... Terry
|
|
|
Post by umhloti on Jun 14, 2012 20:15:29 GMT
Thanx terry .
The constractive critism is briliant. I thought my mortar was to much in the bottom and bricks should have been tighter towards the bottom like you said.
My arches have to be 3 bricks deep to house bbq that 50cm deep
Please see your PM
Lovely work in you example
|
|
|
Post by moorsy on Jun 15, 2012 11:25:27 GMT
Hi,
Would have to agree that building the wall up at the back first might be the answer. Then build the arches out from the back to the front. That way the wall helps support the arches and also acts as a wind break.
|
|