Planning the build
Why build an extension?
Initial design sketches
On-line Building Regs
Meeting planners
 Meeting building control
 Planning the foundations
 Planning the floor slab
 Marking out the footings
 Damp proof course issues
 Possible drainage problems?

 Construction of the walls
 Proposed roof structure
Windows diary
 Window challenges
 Initial window plans
 Making the casements
 Making the frame
 Designing leaded lights
 Making leaded lights
 Assembling the window
 The little window

 The door frame
Demolition diary
 The demolition starts!
 The demolition continues
 Still more demolition

Foundations diary
 Foundation issues
 Drain issues
 Digging the foundations
 Rethinking foundations!
 Pouring the foundations

Floor slab diary
 Rethinking the slab!
 Floor vent extensions
 Preparing the slab #1
 Preparing the slab #2
 Pouring the slab

Walls diary
 Preparing to build walls
 Build up to the DPC
 Build the walls #1
 Build the walls #2
 The gas men cometh
 Build the walls #3
 Finishing the walls
Roof diary
 Roof structure build
 Tiling the roof
 Finishing the roof
 Finishing the gables
 Roof insulation

 Floor screed
 Shower room
 Shower room floors
 Shower room walls
 Utility room
 Utility room walls
 Utility room floor
 Finishing the windows

Project finished!
 Final inspection
 The certificate
 Final thoughts

 Twelve months on!
 Material costs
Sister sites
 House re-roof project
 Home gas usage data

 Stop paint flaking
 DIY secondary glazing


Digging the foundations

Sunday, 8th April (Easter Day): I really had not considered starting to dig the foundations today but I had nothing else to do that I could think of and weather forecast was for hot weather for the next few days.

So out came the shovel!

I uncovered the drainage pipe from my neighbour (don't ask!). This will need to be protected with a bridge before pouring the concrete.
The first bit was dug quite quickly.

I was most pleased to realise that I had not uncovered the gas pipe!

I dug down to the subsoil which is solid sand at my house. Half of the trench was sub soil, while the other half had been previously dug.

This part of the trench will be all at the same depth but the next section will lower so there will be a step in the foundations.

The foundations are to be 600mm wide and 250mm (8") deep.
I'll dig the last section of the trench tomorrow and then peg out to fix the exact depth.

I seem to have achieved a lot in just over a month - I only started building the windows at the beginning of March!
Monday, 9th April (Bank Holiday Monday): First task of the day was to dig the foundation trenches on the south side of the extension.

I soon uncovered the the main house drain - the nearest pipe in the photo on the left. I also discovered the old salt glazed pipe that was replaced by the new drain 20 years ago. I would like to leave this in place as I do not want to disturb it even though it is not used.
A bit more digging uncovered the expected mains gas pipe cutting across the trench.
Digging out the last foundation trench shows the gas pipe following the line of the trench as predicted.
The rest of the day was spent pegging out the trenches to get the levels right. This was achieved using wooden pegs, a long length of wood and a level. Due to the drop, I decided to include two steps in the trench at the points shown by the white shuttering.

I enclosed the gas and the drainage pipes with shuttering. I will fill the foundation trenches with concrete in two stages. The first stage will be up to the top of the shuttering. The pipe tunnels will be filled with gravel and covered with pre-cast concrete slabs. The top layer will then be poured to bring the thickness up to 9". All changed on next page
The same applies to the other pipes crossing the trench at the other end of the extension.

I hope building control are happy with what I am proposing! I will call them tomorrow and try to arrange to get them to come and undertake their first inspection.

The weather is forecast to be very hot for the next few days so I want to get on and pour the foundations before it rains.
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