Help converting standalone garage to warm office room

[ishaqmir]

Hi everyone

am new to this forum and a fairly novice DIYer, although I am becoming familiar with most DIY tasks, and have got myself decent dewalt tools.

right, I basically have a double garage, which has been built very well, it has 2 'up-n-over' doors at the front, and at the back towards the rear garden, it already has a big window and a normal sized wooden door with a deadlock.

i would like to convert it into a warm office room.

i had a builder come over to quote me and he gave me good advice saying that the garage has been very well built and all we need to do is construct studded walls everywhere, insert insulation, and plasterboard it up. (i dont want to change the outside look of the garage btw)

he quoted me £3600 for the job, but im thinking if the majority of the work is all woodwork, I can do it myself, then put up the plaster boards and then get a professional chap to plaster the whole garage for me.

oh yeah, the electrics are also already in place, lighting, power sockets, consumer unit with 4 fuses. i will get an electrician to re-do all the wiring though, and change it to a modern garage RCD consumer unit.

i basically would like help from start to finish, and certain things i need to watch out for.

am I right that all i need is the 6x2 stud work timer to do the job?

and what insulation? i'd like it to be as cheap as poss, but obviously effective too.

the floor is solid concrete and the builder confirmed that it has had a damp proof layer put into it.

generally the garage is very dry and no signs of damp.

also, how to seal off the edges of the two big steel garage doors, as I dont want rain or worse, field MICE!!! getting into the garage through the gaps around garage doors.
i'll be building a studded wall behind the garage doors, insulated and plaster boarded.

also, cheapest place to buy the timber plasterboard etc from?

thanks

 

[pred]

Most builders have an account with various builders merchants, hence we usually get a good deal as we've got sort of loyalty points, Why don't you ask the builder that gave you a quote to source the materials for you?


And yes I am being cynical!!

 

[walty666]

Ignoring the above post, I'm 80% through doing the same as a DIY project. I purchased all the materials (timber, celotex, membranes, flooring, plasterboard, electricals, fixings & sundries) for about £2k. I had builders quoting me between £4k and £6k to do the job (mats & lab) for what they reckoned was a week's work. If you take the material costs away, £2k to £4k for the labour seemed a bit steep, so I wouldn't always assume that the builder will be getting materials cheaper than you can. They probably aren't too fussed about getting the best prices, where as you'll likely be happier to shop around a bit more. I pointed this out to two of the builders who quoted and was met with the same response - 'good luck'. Interestingly they weren't interested in taking the work on as a labour-only contract (perhaps they'd be missing out on the mark-up on the material costs... yes, I'm being cynical)
I got most of my timber and Celotex from 'less2build' - they seem by far the cheapest I could find on the net (it ended up coming via Travis Perkins/Sheffield Insulation anyway...)
Stud work can just be 4x2 assuming it's not structural. I opted for tanalised joists to use rather than CLS, just in case I get any damp problems.
I've put 75mm Celotex between the 4" studwork with a void in front for the cabling.
1200ga DPM on the floor (lapped up the back of the studwork), 50mm Celotex on that, 22mm T&G chipboard flooring on that...
I've stood the studwork about 5" off the walls so as to clear the piers (probably a bit excessive but not short on space). 4x2 topplates screwed to roof joists and 4x2 soleplates screwed through DPM/DPC into floor slab, draped breather membrane from the top plates to protect back of studwork, installed vertical studs and noggins, cut celotex between, 500ga VCL, run cabling and installed k/o boxes in 25mm void infront of celotex, plasterboard over.
To prevent cold briding from the roof joists, I also installed Celotex PL4025 (insulated plasterboard) on the ceiling. This coupled with the 75mm between the joists and the airspcae should get me near a U value of 0.2, walls are about 0.28.
Mine was a double-garage sized shed so didn't have a double up/over door to fill in, just a large single-glazed soft wood bifold patio door which needs replacing before Autumn instead...
It's been a bit of a mission doing it myself (mainly due to other family distractions preventing me getting on with it), but have learnt a lot and saved a couple of grand in the proces...

 

[Porque223]

Rent a room heater attached to a kwh meter and heat the room for a few hours on a cold night for which you know the average outside temperature for the few hours.
Women are more sensitive to cold.

For more accuracy repeat this experiment over several days and nights.

With some formulas and your local climate obtainable from
http://www.degreedays.net/
this experiment will tell you the heat loss in BTU/hr and so you can figure how much insulation of what type you need.

 

[ishaqmir]

Many thanks for such a detailed reply Walty, has given me the push to do it myself, I just need to decipher the jargon terms u have used like vertical studs & noggins.....lol

 

[walty666]

Sorry buddy. Studwork is the timber frame you build inside to form an inner wall. If you stand it off the external wall it'll create a cavity. Vertical studs are the vertical pieces of timber from floor to ceiling, usually spaced out at 600mm spacings to take 8' x 4' plasterboard sheets. Noggins are short horizontal pieces of timber between the vertical studs which brace them and keep them 600mm apart.

 

[ishaqmir]

Thanks for reply

The wall heights in the garage are 2.2m, how many 'rows' of noggins should I use? I.e. what should the vertical spacing be?

You said 600mm apart, is that the space between studs or from their centre to centre?

Thanks

 

[pete47]

Sorry buddy. Studwork is the timber frame you build inside to form an inner wall. If you stand it off the external wall it'll create a cavity. Vertical studs are the vertical pieces of timber from floor to ceiling, usually spaced out at 600mm spacings to take 8' x 4' plasterboard sheets. Noggins are short horizontal pieces of timber between the vertical studs which brace them and keep them 600mm apart.

Building the stud work away from the wall to form a cavity is genius! Never would have thought of that although now it seems obvious.

 

[indus]

Rent a room heater attached to a kwh meter and heat the room for a few hours on a cold night for which you know the average outside temperature for the few hours.
Women are more sensitive to cold.

For more accuracy repeat this experiment over several days and nights.

With some formulas and your local climate obtainable from
http://www.degreedays.net/
this experiment will tell you the heat loss in BTU/hr and so you can figure how much insulation of what type you need.

Fantastic! This is almost as ridiculous as your suggestions to a guy recently who wanted to sound proof his flat.

You suggested he set up a microphone and perform some kind of spectral analysis of the sound frequencies. The icing on the cake was one of your ideas for solving the problem by using sound wave cancelling electronic equipment

Do you take drugs??

 

[AdamCH]

If the walls are fairly flat why not fix Celotex + plasterboard straight to the walls? Insulated cavities are more energy efficient than air cavities so I don't see any advantage in creating a stud wall off the wall to create a cavity and since studs are less efficient than insulation you will get better insulation by fixing unbroken slabs.

Cetotex have a calculator that will show you the effect of different cavities and thicknesses - http://www.celotex.co.uk/Other-Resources/U-value-Calculator.

 

[Porque223]

Rent a room heater attached to a kwh meter and heat the room for a few hours on a cold night for which you know the average outside temperature for the few hours.
Women are more sensitive to cold.

For more accuracy repeat this experiment over several days and nights.

With some formulas and your local climate obtainable from
http://www.degreedays.net/
this experiment will tell you the heat loss in BTU/hr and so you can figure how much insulation of what type you need.

Fantastic! This is almost as ridiculous as your suggestions to a guy recently who wanted to sound proof his flat.

You suggested he set up a microphone and perform some kind of spectral analysis of the sound frequencies. The icing on the cake was one of your ideas for solving the problem by using sound wave cancelling electronic equipment

Do you take drugs??

O, ye of little faith

While I have your attention -
Q: what is an advantage of being fed a steady stream of insults as a kid?
A: you become somewhat impervious to the treatment you will receive later in life.

 

[indus]

Rent a room heater attached to a kwh meter and heat the room for a few hours on a cold night for which you know the average outside temperature for the few hours.
Women are more sensitive to cold.

For more accuracy repeat this experiment over several days and nights.

With some formulas and your local climate obtainable from
http://www.degreedays.net/
this experiment will tell you the heat loss in BTU/hr and so you can figure how much insulation of what type you need.

Fantastic! This is almost as ridiculous as your suggestions to a guy recently who wanted to sound proof his flat.

You suggested he set up a microphone and perform some kind of spectral analysis of the sound frequencies. The icing on the cake was one of your ideas for solving the problem by using sound wave cancelling electronic equipment

Do you take drugs??

O, ye of little faith

While I have your attention -
Q: what is an advantage of being fed a steady stream of insults as a kid?
A: you become somewhat impervious to the treatment you will receive later in life.

Q: Why do you suppose you were fed a steady stream of insults as a kid?

 

[Porque223]

Q: Why do you suppose you were fed a steady stream of insults as a kid?

A: I was the wrong gender.