Garage / Workshop

[Jack757]

Our intentions are to put in a 12M x 8M workshop/garage at the bottom of the garden under permitted development. This to be approx 2.4M and 2M away from boundaries. To have 2 roller doors and single privacy door. No electrics to be fitted yet until main house is built which could be a couple of years after.

This would be the structure, groundworks and installation. Access not an issue.

We are stuck on the best structure to use between insulated steel frame/roof or block with render. I believe brick would be far too expensive.

We are looking for the most cost effective option but also that it will not condensate and is suitable for storing classic cars and working on them (Ramp will not be needed). Ideally would also like to fix whatever we need to the inner walls.

Also being in the country we are prone to rodents so needs to be pest proof and long lasting.

We've had a couple of quotes for steel structures with installation around 40k (no groundwork costs yet) but are yet to look into block.

Anyone got anything similar? Any advice please?

 

[Roger440]

12 minutes ago, Jack757 said:

Our intentions are to put in a 12M x 8M workshop/garage at the bottom of the garden under permitted development. This to be approx 2.4M and 2M away from boundaries. To have 2 roller doors and single privacy door. No electrics to be fitted yet until main house is built which could be a couple of years after.

This would be the structure, groundworks and installation. Access not an issue.

We are stuck on the best structure to use between insulated steel frame/roof or block with render. I believe brick would be far too expensive.

We are looking for the most cost effective option but also that it will not condensate and is suitable for storing classic cars and working on them (Ramp will not be needed). Ideally would also like to fix whatever we need to the inner walls.

Also being in the country we are prone to rodents so needs to be pest proof and long lasting.

We've had a couple of quotes for steel structures with installation around 40k (no groundwork costs yet) but are yet to look into block.

Anyone got anything similar? Any advice please?

 

 

I did exactly this.

 

Steel framed, clad in composite steel panels. Also insulated under the floor and up the sides to meet the cladding.

 

Near perfect thermal envelope. Only messed up at the door way, but thats may fault for not thinking ahead.

 

Same intended use.

 

Not sure how it stacked up cost wise against the options though. But as an outcome, coudlnt have been better.

 

Details here: https://www.garagejournal.com/forum/threads/my-gab-in-the-uk-thread.265998/

Edited March 7, 2023 by Roger440

[Kelvin]

We’re doing the same. 12m x 8m is huge. Ours is 10.5m x 6m and after pouring the foundation yesterday it feels pretty big. We went for 80mm insulated panels and roof with insulation under the slab and under and up the foundation. Our total cost including groundworks, floor insulation and installation is well under £40k ex VAT. 

[Russell griffiths]

Icf blocks. 

Single storey rectangular build with one or two opening will be the easiest thing to build going. 

You could get the blocks up in two/three days with two of you. 

Then concrete pour. 

Roof trusses with a raised cross tie for extra head room, will be very thermally efficient and good airtightness. 

Render outside, 18mm ply on the walls inside and then pink plasterboard. 

Will make the nicest workshop you’ve ever had. 

[saveasteading]

Try a steel portal made of lightweight steel, rolled galvanised sections as the primary steel. @Gus Potteris a bit of an expert on them.

I used the principle only once, and found that the saving in structure cost was equalled out by extra labour. But that was with a super steel erecting team. For DIY or just a builder that could change because it is all more manageable. 

 

If you need it to be heavily insulated then perhaps icf. If it needs solid walls then trad or icf.

For cheapest use timber shed type, but won't last so long and not very high.

For best value open space, with height: steel throughout.

[Gus Potter]

10 hours ago, Jack757 said:

Our intentions are to put in a 12M x 8M workshop/garage at the bottom of the garden under permitted development. This to be approx 2.4M and 2M away from boundaries. To have 2 roller doors and single privacy door. No electrics to be fitted yet until main house is built which could be a couple of years after.

This would be the structure, groundworks and installation. Access not an issue.

We are stuck on the best structure to use between insulated steel frame/roof or block with render. I believe brick would be far too expensive.

We are looking for the most cost effective option but also that it will not condensate and is suitable for storing classic cars and working on them (Ramp will not be needed). Ideally would also like to fix whatever we need to the inner walls.

Also being in the country we are prone to rodents so needs to be pest proof and long lasting.

We've had a couple of quotes for steel structures with installation around 40k (no groundwork costs yet) but are yet to look into block.

Anyone got anything similar? Any advice please?

 

That's a lot of tough questions!

 

Ok my thoughts.

 

Well you are at least 1.0m away from the boundary so that eases the fire boundary conditions which opens up the opportunity for a light weight cold formed steel frame or a hot rolled steel frame.

 

Next is your budget and your expectations. A lot of folk think a garage should be like a house.. yes it needs to stay up as long as a house and be safe but in the main it's an unheated building and not occupied.. I'll come to the cars in terms of keeping them bonish dry in a bit which is different.

 

Assuming the garage is 8.0m wide and 12.0m long then it becomes hard to make modest masonry work without piers, wind posts and so on. Much also depends on your eaves and ridge height.. that is a big driver.

 

My first thoughts.. you have cars so maybe have practical skills so would be comfortable around a hot rolled steel portal frame and an attention to detail.. be able to measure! Two gable frames with a central frame, purlins between.

 

Floor slab.. well you can do what is sometimes called a tied pad found for these small buildings.. here the DPC / DPM is not continuous but if you treat this as a workshop / garage, pour and compact the concrete well then to all intents and purposes the concrete is waterproof.. that is where the savings lie for example! A tied pad found has a slab that has the pads under the columns cast at the same time.

 

Best thing to do is to post some sketches of what you are thinking about and we'll all chip in.

 

If you are storing classic cars then you really have to stop dripping condensation from the roof. Normally we use a default of 40mm PIR on the roof in an unheated building. Depends on your location but if more up North or say in Linconshire the maybe 60mm PIR is a safer bet.

 

In the round though need a bit more info to contribute constructively. Things that would help.. eaves height and what temperature you want to store the cars and work in when you have time off. Then we can play.. what about an engine lift / hoist?

 

 

 

 

 

 

 

 

 

 

[joe90]

As it’s over 30 sq m you need building regs!. My current workshop/garage is 7.5m x 10m, no insulation in the floor or block walls, roof is steel on battens with membrane over trusses and suffer no condensation despite no insulation. Yes it’s cold in winter but perfectly dry.

[Jack757]

@Gus Potter Thanks. So this is an image of what we have been quoted on so far which is what we were potentially looking at for a steel structure. 12x8Mx2.4M to eaves. 2 manual roller doors, and privacy door.

40mm insulation to walls and roof, just the cost seems very high without groundworks cost, whatever that will add on.  We've got a house to build after so don't want to go to OTT with the workshop funds. 

We are in the East so cold not too much of an issue, he can add electric heaters in the future if he's too chilly!!!  No lift/hoist needed.

To be honest we are so busy we would rather just get someone to do the lot and it means we don't have to be on site either. 

 

[Jack757]

@joe90Thanks. The old existing garage which is block and render was pretty watertight and not too noticeably cold (no insulation) until recently when the roof started leaking, however it is now over 40 years old so no surprise. That is partly why we are thinking of the same opposed to steel, although without the flat roof!

I'm presuming the architect will factor building regs in, wouldn't he? I haven't instructed him further since our last meeting and we need to start getting on with this soon as want started before house plans move forward.

 

We know nothing about building and this kind of thing so quite a learning curve and wonder what on earth we are doing!!!!

[saveasteading]

42 minutes ago, Jack757 said:

We know nothing about building

None of us did at first. 

You have 2 choices: learn a lot about building or hand it to experts and pay them well.

 

We are here to help of course.