Extension Brick/Block Work and Foundations

[Gravyspoon]

Hi all,

Embarking on a small extension on the back of the house. No knocking through required, just using existing window and door openings. I've spoken to BC for some of the technical info, and am intending on doing a chunk of the work myself as much as possible.

My questions are as follows though:

1. Getting quotes for the block and brick work. There will be approx 1500 bricks, and 350 blocks (including below ground). Generally, what sort of figures should I be expecting for these to be laid? The bricks will be furfixed to the existing house, and other than bricking around new window and door opening, hopefully nothing too specialist.

2. I will be digging the footings myself and BC have indicated that the existing footing depth of 1m should be sufficient (hopefully). One strip will meet up with the corner of the existing house, the other will finish about 200mm from the party wall. Both trenches 600mm wide. I know I'll need to sort out the PWA, but suddenly paranoid about digging near the existing footings. Soil conditions round here are good (reason for the depth is the woods next door). Is there any real risk of undermining the existing foundations of the house while digging the trenches, or am I just worrying about nothing? Won't be touching the existing structure, just joining to it. The distance between the inside edges of the trenches will be approx 2850mm.

Any helpful comments appreciated!

 

[^woody^]

The quotes will tell you what you could expect for your job, on your site, in your part of the world. If someone on here tells you they will do it for a cheese sandwich, that's not much of a benchmark.

Don't worry about the trench and your house foundations. Just try and fill it with concrete as soon as possible before it gets filled with rain.