One of the tricks to save on renovation costs is to make sure that you order the correct materials at the correct amount. That is why I’m giving you some simple tips on how to compute for the right amout of materials in this latest blog.
Based on my experience with self-build property renovations, 1m³ of concrete usually lays 7m run of foundation. Remember that this is just an estimate, since trench width varies from house to house and the bottom of the trench may not be completely level.
To find out how much m³ of foundation you’ll order, measure the full length of the foundation trench and divide the number by seven.
Foundation walls up to the DPC can be made with either of the 3: a cavity work in dense concrete block, engineering bricks, and trench blocks.
Calculating for how much foundation you’ll buy is almost the same with the formula concrete. The only difference is that walls have an average height of 1m.
If you’re planning to build the foundation in blockwork, you have to calculate the face brickwork first. Regularly, face brickworks on the foundation should start at least 150 mm below the finished ground level.
This one is simple. First, multiply the width by the length of the floor to get its area. After getting the product, multiply it by the depth for the concrete and sub-base volume.
The crushed and consolidated sub-based are usually 150mm deep and could be MOT Type 1 or perhaps hardcore. This should be blinded with sand first before receiving the damp-proof membrane (DPM).
In calculating for floor insulators, on the other hand, you’d first have to determine if it’s going above or below the concrete. If it will be installed below the concrete, you’d have to order enough material to cover even the edges. 1M³ of concrete usually covers a floor area of 8m².
Multiply the length by the height (less any openings for windows and doors) to get the area of the cavity walls from DPC to the roof. Starting from ground floor to the first floor joists (if it’s a two storey building), and then from the joists to the roof is the best way to measure the area.
After getting the area, just multiply the value by 60 for the quantity of face bricks and 10 for the blocks. Some builders add 10 per cent to their order to act as reserves in case the blocks break during shipping.
The building plans or renovation checklist should indicate what type of timber grade is required, because they’re not sold in a “one size fits all” basis.
Timbers for roof are sold in standard lengths of 1.80m to 6.30m at 300mm intervals.
Structural timber also comes in different grades: C14, C16, C18, C22, C24, TR26, C27.
Just like in timbers, the required roof tiles for the build must be indicated in your property renovation checklist, because the number of tiles you’ll order depends on what type you’ll use.
You’ll need approximately 60/m² for plain rood tiles, but if you’re using concrete interlocking tiles, you’ll have to check with the tile manufacturer’s catalogue to find out how many are required per m².
Hopefully, these tips will help you budget your project accordingly and minimise your costs.