Concrete sectional garage - removing some panels

[Bert Coules]

I have a (quite old) concrete sectional garage and am wondering about converting it for use as a workshop. My main question is this: would it be possible to remove several of the 16" wide sections from one of the long sides and replace them with a timber frame which could hold a door and a window? I'm thinking that this might be easier than cutting two separate openings into the existing intact concrete wall.

The panels are bolted together near the top and bottom, and are also fixed to the wooden beams supporting the (corrugated metal) roof. I don't think they're bolted to the concrete base: they appear to be kept in place purely by their weight.

Assuming that I could undo or cut through some of the bolts (and release the fixings to the roof beam) could say three or four of the panels then be removed without affecting the rest of the structure? There would still be several panels left standing either side of the gap, and that's a huge amount of weight to leave relatively unsupported, even for a short time: I'd like to know in advance that everything would be stable while I fitted the timber frame.

Many thanks.

[geoff]

In message , Bert Coules writes

Is it a Compton or a Banbury or other make?

[John Rumm]

I know the sort of thing - tall full height panels, about 18" - 24" wide. Rafters run across the width every so often to take a traditionally corrugated roof.

Can't see any problem having a few away.

However, to be certain, make up a wide dead man prop[1] - to span the width of the section you are taking out. Stick that under the ends of the rafters that will be unsupported before you remove the wall, and kick the leg in place so that it is taking the weight of the rafter ends. Then take out the panels and build your frame in.

[1] i.e. a more robust version of this made out of a couple of lengths of 4x2"

Assuming that I could undo or cut through some of the bolts (and release

What's the roof made from?

[Bert Coules]

Thanks for the reply. I've found no identification anywhere on the structure (it was already here when I bought the property). Does the brand make a difference to what I'm considering?

[geoff]

It does to how the panels are held in place

If its a compton, you should, if the bolts aren't too rusty, be able to lift the "above" panels and lift out the required panel

with a Banbury, they are held together with mastic which can be a bit more of a challenmge

[Bert Coules]

Geoff, thanks for the reply. I'm a little puzzled by your reference to 'the "above" panels' - the panels of my garage are approximately 16 inches wide by 6 feet 6 inches high, and the height of the structure is the height of the panels (plus a little extra for the roof) - there are no above and below components.

[geoff]

In message , Bert Coules writes

Then it is neither of the above in that case (the two most common makes)

I think you would need to put a brace across when you remove the panel as there is little else to maintain structural integrity

[Bert Coules]

Geoff,

On closer inspection, it looks as though the panels are just butted up against each other: it shouldn't be necessary to lift them out since once the bolts are removed or cut they should just come away. But there does seem to be mastic in the butt-joints, so possibly my garage is a Banbury.

[Nick Odell]

I'm imagining something like this - gleaned from a search on Google images -

there a better example to be found from searching on the web or would you be able to upload a picture of your own and post the url here?

Somebody might have already written a monograph on the distinctions between the construction of various prefabricated buildings and may have even enumerated the hundred and forty forms of fly-ash to be found in the concrete composition of the same but I think in this instance a photo may prove more useful :-)

Nick

[Bert Coules]

perspective slightly exaggerates the slope of the roof. In fact, the vertical concrete panels are all the same dimensions and it's the height of the timber cross-pieces which reduce from the front to the back. The metal (tinplate?) roof edging strip is actually 90 degree angle and covers the gap between the tops of the panels and the corrugated sheets:

side wall in the first photo is the one I'm contemplating opening up.

I think you'll have baffled a few readers with that, but I appreciated it! Thanks.

Bert

[John Rumm]

I know the sort of thing - tall full height panels, about 18" - 24" wide. Rafters run across the width every so often to take a traditionally corrugated roof.

Can't see any problem having a few away.

However, to be certain, make up a wide dead man prop[1] - to span the width of the section you are taking out. Stick that under the ends of the rafters that will be unsupported before you remove the wall, and kick the leg in place so that it is taking the weight of the rafter ends. Then take out the panels and build your frame in.

[1] i.e. a more robust version of this made out of a couple of lengths of 4x2"

Assuming that I could undo or cut through some of the bolts (and release

What's the roof made from?

[Bert Coules]

Exactly so.

Thanks for that. Only one rafter will be affected by the wall removal if I stick to my current plan, but it's clearly a good idea to support it until the frame is in.

Some sort of thin plated steel, as far as I can tell.

Bert

[John Rumm]

OK seen your photo now. In which case run a 4x2 along the top of the concrete panels on the inside. Fix it at both ends to the face of the the edge ones that will remain. You can then take out the ones between and it will hold the end of that rafter in place until you get the frame it.

Its not going to be carrying much weight - mostly itself a a bit of tin roof that will me mostly supported anyway by the looks of it.

[Bert Coules]

Thanks for the thought: I had wondered about that. But I rather think that the 4x2 will obstruct the removing of the panels, which will have to be tilted inwards at the top: they can't tip outwards because the angled roof-capping strip is in the way. Unless they could moved inwards at the bottom end first, and that's surely not the ideal way to handle something that weighty.

So perhaps a single prop to support the one central rafter is the way to go.

Bert

[fred]

Plastic coated not plastic. Double skinned with an insulation inter layer as used on 99% of industrial units built in the last 20 years or so. I used them on my workshop which is now about 15 years old and have NEVER suffered from condensation drips from the roof.

Condensation is caused by a temperature and humidity differential. Doesn't have to be cold. If you lived in a humid client you would get condensation despite the heat. The best answer is good ventilation to allow the inside and outside temperature/humidity to equalise..

Double skin rooflights as suggested are manufactured from fibre glass which you will not cut with a knife. The other point is, if the scrotes can't see (through a window) what is inside they are unlikely to climb on to a roof and hacksaw their way through two layers of fibreglass on the off chance there is anything worth stealing inside. And then having to go to the trouble of climbing down inside and passing the stolen items out through the hole in the roof.

Any your average child knows how to cut a glass window without making a noise.

Paul Mc Cann

[Bert Coules]

I'll have a search around. Is there a particular product you'd recommend?

That sounds fine for the summer but (literally) not so hot in the winter.

Bert

[Bert Coules]

Just to add an update: on tentatively examining the panel-joining bolts today to see just how much effort would be needed to remove (or cut through) them, I discovered that every single one is rather less than finger tight. I could remove the entire wall with no tools other than my hands.

Bert

[Geo]

Yehbut - keep it quiet - you /will/ need to buy some new tools for the job...

[Bert Coules]

Ha! It's true, it's true...

Also, I suspect I'll need some burly assistants. I've never seen one being put up, but I reckon those concrete panels (6ft x 16") are going to be pretty weighty.

Bert

[marcleethompson]

Hi reading this to see if it could help me I've been given a 10x30 garage c oncrete garage with 16" panels with marley tiled roof which has steel 4x2 b ox section angled to support roof 28degree pitch .what I want to do is make it 16x20 by rearranging panels and welding extra steel in the truss length to keep the same pitch .What I dont know if the concrete panels will be st rong enough to take the extra weight of the roof any input much appreciated . Marc