If you’re considering second-hand materials, it’s worth looking for:
• bricks – you can expect to pay half to two-thirds of the new cost – but they are a good source for small quantities (1,000 or less) or special bricks. Treat bricks that aren’t clean with some circumspection: check that any residue will clean off easily – cement-based mortars don’t
• timber – especially beams, floorboards, staircases, doors and window frames. Old timbers will be seasoned,
so should not warp when used. Avoid timbers that show any signs of rot or insect damage and treat with preservative, if necessary woodworm fluid, before installing.
Superficial damage to the surface of planed wood can usually be sanded out. Rough sawn structural timbers can be planed and sanded if you intend to expose them, but working the timber like this may then cause it to move in use
• rolled steel joists – these de‑teriorate very little, any rust is usually superficial
• roofing materials – slates are usually available for about half the new price. Old clay tiles may occasionally be found but are expensive.
Consider also radiators, quarry tiles, fireplaces, ironmongery, stained glass windows, mirrors, Victorian or Edwardian sanitary ware. Even old taps can be salvaged – there are firms who will rechrome them for you.
Good hardcore is composed of material which is free from large lumps, rubbish (especially plaster, timber, plastics and metal) and chemical contamination. Hoggin (clayey gravel) is suitable and is obtainable from sand and gravel suppliers or builders’ merchants in many parts of the country. If hoggin is unobtainable, crushed stone is a good substitute. True hardcore – clean, well- broken concrete – is also an excellent sub-base material but is almost impossible to get: what is now usually advertised and sold as ‘hardcore’ is actually unsorted ‘as-is’ builder’s rubble and is unsuitable except as fill material. Avoid clinker, which is likely to contain sulphates.
A large and ambitious project like an extension will usually need tools and equipment that you wouldn’t normally use or have room to store and for these jobs hiring is one answer. You can hire almost anything – even a bucket. Any job is easier with the right tools and it’s usually worth the saving in time and effort and the quality of the finished job to hire special tools for small jobs as well as the big ones when you couldn’t cope without the proper equipment. The top ten list of hire items includes things like cement mixers and ladders. Some others worth considering are a carpet stretcher, pipe freezing kit, creosote spray unit, pipe bender, drain rods, steel props.
Where to hire
Hire shops are listed under Hire Contractors in local directories and these days some d-i-y superstores have hire counters. Hire shops are usually helpful, if they don’t have what you want, they’ll often get it from somewhere else or recommend another shop. In past surveys Which? has found that hire rates in one shop could be as much as three times those in another so it’s well worth shopping around. On the whole, larger corn-
panies with several branches have tended to be more expensive than average. Note: hire departments in superstores are often branches of larger companies.
Length of hire
The shortest hire can be from 4 hours – a morning, an afternoon, or overnight if you collect after 5pm – but some firms have an eight-hour minimum much notice they need for the firm delivery date and find out what arrangments they have for stopping the delivery if the weather is bad.
For small loads some firms now offer a mini-mix scheme, where the concrete is mixed on site in a special vehicle at a speed to suit you.
The strength and durability of concrete which has been properly mixed and laid depends to a large extent on its cement content: the richer the mix, the stronger and more durable it is. The three basic mixes which cover the majority of jobs are C7P, C20P and C30P. When ordering ready-mix, all you have to do with some depots is to quote the mix number together with the type of cement (ordinary Portland), maximum aggregate size (normally 20mm), workability (high) and any special requirements.
Of the three basic mixes, you’re most likely to use C20P, it’s a good all-round mix, especially for ground slabs and floors and paths of 75mm or greater thickness. The BS specification (kg per cu m approx) for this mix is cement 300, fine aggregate 700, coarse aggregate 1170. Or if batching by bucketful I bucket loose cement, 14 buckets damp sand, 24 buckets coarse aggregate or 1 bucket cement, 3
buckets all-in aggregate. If possible, use separate aggregates. The Yield per bag of cement is approximately 170 litres; approximately 6 bags pf cement per cubic metre of concrete.
The yields given for C20P is for finished concrete. When calculating the volume of concrete required, remember that excavations for foundations, ground slabs and so on are rarely accurate, so err on the generous side.
For foundations and other fairly deep work, multiply width by depth by length to get the volume. Irregular areas can sometimes be dealt with by dividing into rectangles and triangles. Really irregular areas are best handled by sketching them out to scale.
imum hire period; others a 24-hour minimum. Some larger pieces of equipment and some very small pieces are hired only on a weekly rate. It makes sense to plan your work efficiently around a piece of hired equipment.
Most firms will ask for a largish deposit when you hire, this may be a cheque which they return when you return their equipment clean and undamaged. Sometimes they also want positive identification such as a driving licence. Some shops go as far as taking your photograph which they develop only if you don’t return.
An alternative to hiring
With any large d-i-y project, the chances are that you will take longer over it than a professional would, and if you slot the work around your normal working day, it can take months (or years) rather than weeks. Hiring equipment for such extended periods would be very expensive and an alternative is to buy with the intention of selling later on. If you buy second-hand, it may even be possible to make a profit, or at least break even on the costs of the equipment. Which? members have done this successfully in the past with things like scaffolding and cement mixers.
For large amounts of concrete, ready- mixed is much easier than making your own and may well cost less than just the materials for mixing your own. You should also be able to depend on high and consistent quality. The minimum load is usually one cubic metre, most lorries carry about 6 cubic metres.
When phoning suppliers for prices you may find that the cost depends on how long the lorry has to stay on site – so discuss this with the firm, agree the time the lorry will stay and muster enough help to deal with the concrete in that time – you’ll have four hours at most to lay and compact the whole load. Check with the supplier on how
VALUE ADDED TAX
Whether VAT is payable on building work is uncertain following a series of legal decisions which cast doubt on the criteria adopted by the Customs & Excise. The following was the situation in early 1983, but it is worth checking with the Customs & Excise office. Don’t take a builder’s word, we’ve found they sometimes get it wrong.
Zero-rated (no VAT to pay) Many services, materials and fittings used in building work are currently zero-rated for VAT purposes. There is no VAT to pay on the supply of services used in the cause of construction, alteration or demolition of a building, and if you have the work done for you there is no VAT to pay on the materials used in these cases. So if you have an extension or a conversion built, have two rooms knocked into one or have a bathroom built in an existing room you don’t have to pay VAT.
To qualify for zero-rating, the work must in its own right be an alteration to the existing building.
VAT is due
There is VAT to pay on any job which comes under repair or maintenance of a building and the hire of tools or equipment used in any building work.
Some work is neither alteration nor repair or maintenance and VAT is charged. This could be jobs like converting a fixed window into an opening window or bricking-in or unbricking a fireplace.
If you do the building work yourself, you have to pay VAT on the materials, and you can’t claim it back.