New Project - Office

[coolcatkelso]

Hiya guys

I'm looking at replacing my current metal shed (office) with a new Breeze Block office, 3.5m x 3.0

I have worked it out to be roughly 300 blocks needed, 1.8 to eaves and 2.2m to ridge?

What I'm wondering is the founds..

Do I need anything seriously heavy? Would 2 / 3" thick concrete be more than enough as the ground is quiet solid anyway? or MUST it be 1ft of hardcore etc and 1 or 2 blocks below ground?

I was thinking of just 3" concrete with polythene underneath, then start building on it once set?

I have a tight budget of around £800 / £1000 max

I assume rafters would be set at 600mm?

Cheers

 

[i_am_fubar]

Oh, I know that sort of project. Especially when money is tight.

First off, are you sure you want to go block? A good timber one may come in cheaper than a poor block one.

What will you be using it for? Just desk work, or tool use, storage... etc?

I would also say don't skimp on foundations. You can re-build or upgrade the shed in the future. You can't upgrade the foundations easily.

What is the reason for wanting to go blockwork? Noise reduction, warmth and general environmental resistances, supporting equipment, permitted development aspects... etc

Also, what style will the roof be, and what material? This could quite possibly cost more than the foundations or walls.

When you say breeze block, do you mean the ultra light weight ones? Bare in mind that these are permeable and damage easily. What were you going to do about waterproofing them? Render is an option, but won't keep you dry without additional barriers and membranes.

I image you want power there? How will you get it in.

A point about foundations. if you simply pour a tray of 3 inches of concrete that size, it will start to break up within a year. Ground heave, tree roots, frost, and even some weeds will tear it to shreds.

Or are you talking about strip foundations? They'll be worse.

I would say, dig no less than 12 inches down. Although it may well need to be more to conform to regs. Even if you don't lay that thick of a layer of concrete at the bottom and build up with foundation blocks, it'll be better.

Personally, I wouldn't entertain the idea of going block work for that budget. I would put some small piles into the ground (cheap if you do it by hand, and easier than digging strip foundations), and go for a suspended timber shed. It may only last for 20 years if you don't care for it. But regular maintenance will keep it going longer. It'd also look nicer than bare blocks.

Fubar.

 

[coolcatkelso]

The construction would be 440x215 Dense Block, it will be plasterboarded internally and rough casted externally.

The roof will be 16x10 Spanish slates with Zinc Ridges

Trusses I would be expecting to use 8x2s

The office will consist of printers, computers, telephones & desks, nothing too heavy

Electricity supply is currently installed in the metal office at the moment and this will be transferred to the new office.

I am a roofer, so materials for the roof are left overs from various jobs, therefore, no costs.

Brother is electrician and again no costs

I will be building the blocks myself so no labour charges.

Working it out, it should come in at £850 for everything, depending on base.

I have a metal shed and with the heat from PC's and heating in winter, it condenses badly, so concrete with slated roof should do better with warmth.

Also, metal shed has no windows and its like a green house in the summer.

Not keen on timber, would prefer a solid structure which will also be nicer for customers visiting etc

How about if I dig down with mini digger, and lay 1 / 2 tonne hardcore type 1 and 3 / 4" concrete, surely this would be enough?

Cheers

 

[i_am_fubar]

Ok, so your roof'll be a goodun.

The idea of foundations is to supply a solid connection from the wall to the ground. As such, don't put hardcore below them.

As a general rule, you dig down to stable dirt, then back fill with C30 strength concrete to within 150mm of the surface (below the frost line). Then lay a course of foundation blocks and then your walls on top.

If you're worried about the cost of the concrete, digging and removal of soil. I would suggest going for strip foundations dug to the correct depth, then using a suspended floor hung from the block work. Just makes sure to Nuke any weeds under it, weed suppressant membrane the dirt and basalt the membrane down - additionally - vent into the floor void.

Fubar.

 

[coolcatkelso]

Cheers guys

spoke to a lad today and I got this advice from him

Dig out the boundry about 2ft wide x 2ft deep and lay 1ft concrete foundation. Then lay a course of blocks with DPC to ground level. Add a second layer of DPC and continue to build up @ 5 block heights max per day.

As the ground is solid anyway, pour concrete 2 sharp sand, 1 building sand 1 cement and aggregate for internal floor.

Install roof beams @ 600mm, OSB boarding and felt

Comes in at £875

Sound ok?

 

[i_am_fubar]

Much better for the foundations. Was thinking today that a strip foundation with infill would be an idea.

Do make sure that you don't have any thuggish plants lurking in the soil before you lay the floor.

Also, if the budget stretches, stick some insulation in the floor.

What are you doing for windows / door? e-bay is great for second hand windows (inc. glass) they're great if you can design your building around them.

Be careful about the cost of the 'misc.' items sneaking up on you. Screws, metalwork for the roof, sand and cement for the mortar, floor paint, conduit, sockets & cable (if they need replacing)... etc.

My flat roof project went up over £200 just factoring in miscellaneous fixings and metalwork.

Fubar.

 

[i_am_fubar]

Also, assuming you know people in the trade, see if you can score any C16 timber offcuts, excess cement near it's use by date, old windows, old laminate floor... etc.

Fubar.