Using a brick garage as a workshop

I have recently moved house and will be converting a detached brick the garage for use as a workshop, this subject has been covered in some forms but I can't see for a brick garage.

Looking at the floor I need to repair it as it is uneven and some of a skim top coat that was there is breaking up, I will remove any loose or hollow sounding areas of the old skim, but then what? I was looking at something like **LINK** has anyone else used this type of material? I was looking to do this in 2 pours so that I can move my lathe from one end of the workshop to the other once the first pour has set, the first pour being up to a wooden batten.

I don't intend to put insulation/wood on the floor as I hope to get larger machines and don't want to loose much headroom.

When it comes to the wall I was looking to insulate as shown in the second image here **LINK** but instead of plasterboard on the inside I am planning to use plywood so that I can screw hooks, shelves etc. where I want in the future. It seems to me that there is a damp-proof material behind the timber uprights, additional timber to keep the insulation of the wall maintaining an ir gap then the insulation, then ply, although the text says to use a membrane if the insulation is only between the timbers, I assume before the ply where they have additional layer, would this be affected by screws? Where there are pillars in the wall there would be no insulation to create a flat wall. Does this seem reasonable?

The roof is currently corrugated sheets on timber cross members, I was planning on adding beams at 90 degrees to the current ones and insulating between these as per the walls, then finish with either thin ply or possible white hardboard.

There will be a side door replacing the current single glazed window, I plan on this being a modern insulated door, if it has glass it will be obscure. The main door is currently a pair of wooden doors, I want to still allow occasional use of these so was thinking of either adding insulation to these or creating a removable wall behind, increasing security and insulation.

Whilst this solution may not achieve the specifications for living areas does it sound a reasonable compromise between cost, comfort and space lost?

Hi Baldric,
Make sure you have a damp proof membrane in the flood so you do not have an unwanted source of moisture that raises the humidity.

Les.

Les,

I can't see one in the floor, there is one visible in the walls, if put a DPM on the floor then put 1-2" of screed on the floor it will be above the DPC in the wall, is this OK? What is the minimum thickness of screed I could put on a membrane? For info the current floor is about 2" above the level of the drive already, I am not sure if that is original or not.

Baldric

Hi Baldrick,

my workshop is a single skin brick built double (tandem) garage. My previous garage workshop was also single skin brick and when we first moved in from new it let in water like a sieve. I was told that it would eventually seal itself which it did but it took about 4 years and this took it's toll on the workshop equipment.

When I moved into my current house all I had was a single garage that was made from Cement Asbestos sheet and timber. As part of the deal with SWMBO I was allowed to have a workshop built. The asbestos garage was left where it was and housed my workshop equipment until the new one was built.

Before moving the equipment into the new workshop/garage I lined the walls with insulated plasterboard 27mm thick. After putting up the plasterboard I also fitted/glued 4mm thick foam plastic from waist level down to protect the walls from scrapes from things such as motor cycle handlebars.

I have several machines and bits of equipment that have been in there since new and they show no signs of rusting and I can confidently leave things for as long as I like and there is no signs of corrosion evident.

Hi Baldric,
I don't know the minimum thickness of screed you could get away with. When I built my workshop I used compacted hardcore covered with a layer of sand (To avoid the hardcore puncturing the membrane.) then the membrane then 5 or 6" of concrete. I later covered this with quarry tiles as the concrete always had a dusty surface. I do not know how you can tell if there is a damp proof membrane unless you can see it coming up between the edge of the concrete and the wall.

Les

There are a number of self levelling compounds available, some will cope with a thicker layer than others, although they are called self levelling they only do this up to a point and still need to be worked level. If the floor slab does not have a DPM then one can be added over the self levelling compound.

Most garage floors are below the damp proof course so this needs to be taken into consideration when lining the inner walls. Should be easy to see where the DPC is as it should be visible inside or outside.

As far as the ceiling/roof is concerned do not forget to leave a air space above the insulation else you could get damp and increase the chances of rot in the timber roof structure.

Time to make a cosy workshop

Bob

Hello Baldric,

You can always drill a test hole in the floor and see what comes out, I mean a decent sized hole and look for plastic in the dust; If there is a membrane then back fill the hole with silicone sealant to restore a dpc and close with cement.

If there is no dpc then I think your best solution is to remove the old slab and re-lay it correctly, finishing below the dpc in the walls.

A white ceiling reflects light and will make it nice to work in, but I would use insulating board finished with white emulsion paint. Lots of insulation overhead and as much as you can spare in the walls before finishing as you suggest. I would also be logical over cable runs in the walls, even to marking their positions or at least take photos.before closing up. Heating might be best with a simple convection heater, wired through a thermostat and backed up with a small de-humidifier. Interwoven chain link fencing strategically placed will slow down those intending to break in, even under the roof sheets in a high risk area. I assume those are fibre cement, easily torn off by baddies.

Regards Brian.

Edited By Brian Wood on 17/05/2015 18:45:39

There are masses of self levelling compounds, the one you linked to's main claim to fame seems to be that its sets so quickly. I am not sure that is you prime consideration. Please check that your floor is reasonablely horizontal, a mate of mine tried our one of these compounds in his kitchen - it all ran down into one corner!!

This would be a better place to put your questions :- http://www.diynot.com/

Frank

Blimey! that's a lot of hard work never mind cost!

Bob

Edited By Bob Brown 1 on 17/05/2015 19:02:20

Hi Baldric, your link is for a compound suitable for up to 20mm which should be more than enough for a damaged existing floor. There is another version for thicker layers, but I'd suggest keeping it thin and not raising above the DPC.

My workshop is a concrete walled garage on a concrete base, I put down a DPC then layers of dpc to stop scuffing and laid timbers across the floor at 10" spacing, I then put thick OSB on top and it has remained flat and firm (and warm and dry) ever since. If I had a much heavier lathe I would have put reinforcement under the legs.

Neil

If it might be used as a garage again (ie doors not bricked up) then there is a planning requirement in hte UK to have a slope towards the doors so that spilled petrol runs out.
If you can see then DPC on the inside then it is not linked to one in the floor therefore probably not one in the floor. It is not normal to have one for a garage as cars are waterproof. (it is in the wall still to protect the wall from damp and subsequent frost damage).

I suggest a skim to provide a smooth surface, DPC joined up to the one in the wall (I wonder if good old hot bitumen is still available) 2 in cement on top.

I did my walls much as you second link, floor with mastic asphalt. You have to pay someone to do it, but it's very quick and very good, flat and damp proof

If the existing screed is breaking up in places I would suggest complete removal, then brush on bitumen damp proof course taking it up the walls to the existing DPC. Re-screed with Portland cement and sharp washed sand, 'polish' a finish to the screed with a steel float. Before use apply a good quality floor paint to make cleaning up a doddle.

All,

Thanks for the responses so far, I will have to drill a hole to confirm if there is a DPM somewhere underneath.

I am loathed to take up the old floor unless it will take time and make a mess. I don't have anywhere else to store my tools/lathe so can really only do half the floor at a time which will be a pain. Before moving I did build a timber framed workshop on a purpose built concrete base, doing this I found I didn't have the knack to get a top screed flat, hence the thought of using a self levelling compound.

Baldric

As it is a garage I doubt you'll find a DPM and even if you do I doubt it goes up to the DPC, that leaves you with three choices

1. Just screed the floor with a levelling compound.

2. As above but an additional surface DPM over the top of the screed with something on top of that to stop wear from foot traffic.

3. Remove the slab and start again.

My garage floor does not have a DPM and at present has not presented any problems RH has been reasonable, I have a max min RH/temp gauge to monitor the situation.

Bob

Hi Baldric & all...

The first question I'd ask is what age is the house possibly assuming the garage was built at the same time. That may give an idea of the building regs that it was built to if any! You mentioned that the brick work had a DPC. If the DPC is above the floor level I would expect that there is no DPC under the concrete slab. The garages that I've come across with building projects may if your lucky have a reinforcement in form of a mesh. The concrete slab I would expect to be 3" to 4" thick. When garages are converted to accommodation a DPC is installed pior to screeding or floor joists are laid on a DPM.

Just a few thoughts on the topic - I'm no expert but have a bit of practical experience - I leave the advice & consultancy to my nephew who is a Civil Engineer. I have the same problem with a single skin on brickwork badly extended with the dreaded corrugated cement asbestos roof which sweats prolifically in the winter even with no heating what's so ever. The plans for a new garage/workshop are on the drawing board or should I say the CAD system!

John

Edited By Johnboy25 on 18/05/2015 09:02:18

My workshop is my garage, no insulation, corrugated roofing material, I have no leaks and dont suffer from rust, I put heavy blankets over the lathe if I think it needs it, and if I dont go in there for long periods I spray WD40 over bare metal.

Martin P

I once tried to level out a area of uneven workshop floor with a self levelling mix, probably ok for domestic work ,not very good for workshop, accidentally drop a heavy object and the surface shatters,so for economy use the self levelling com[pound ,then floor paint or a thin membrane then a layer of 19mm chip board,chip board has lasted for 20 years in my workshop used daily,recently I had to replace an area in front of my lathe where constant standing and the occasional spay of slurry from the chuck eroded the board,I used ordinary chip board. It keeps your feet warm and if you drop a precision tool or piece of work it does not get damaged,chip board will support large machine tool ok, my 1and 3/4 ton mill has sat on it since 1990. Brick walls,in heavy rain does the inner side of the wall get damp? if it does dont fit an inner lining until you can stop the rain,I built my double garage and workshop in brick to match the house the end gable wall is nine inch solid brick and faces the weather,and rain came through and even after several years it never sealed so I had the exterior wall rendered,not nice to look at but waterproof.Eventually I used the garage for storage and built a timber worshop .Now be careful with problems with vermin ,mice will get into buildings and love insulated cavities,keep all wiring surface mounted and visible if the cables go through the insulation use steel conduit. Down the road from me there was a large pitched roof double garage converted to a gym and living accomodation , it burned down last winter,completely destroyed, cause determined by fire brigade and insurers ,mice chewing through the wiring,luckily the garage was detached.

Hi Baldric

See my posts.. re converting brick garage.. for your delectation, cogitation...

**LINK** ..

**LINK**

**LINK**

**LINK**

Have also posted some pics of conversion in progress in my album 'miscellaneous'... others will no doubt have differing methods of insulation, lighting, heating etc. but hopefully the above may assist you.

George.

Edited By mechman48 on 18/05/2015 10:45:00

I did this (the plywood). You can also put your electrics on the inner surface of the plywood, in trunking - which makes it much easier to move/add sockets and completely removes any possibility of drilling through a mains cable when fitting shelves etc. I got a qualified electrician to provide the supply to the building, fit a distribution panel, and put in the lights and a mains-ring at the top of the wall. I then added and wired in the sockets exactly where I needed them for each machine (I hate trailing extension leads) and the electrician came back and checked my work over for me before I switched it on.

Edited By Bob Unitt 1 on 18/05/2015 10:43:53