This type of roofing is used on nearly flat roofs and is composed of layers of roof­ing felt coated with hot asphalt and then topped with pea gravel. For home use, this type roof might be found on carports, over patios, and on homes with low-pitched roofs.

It’s often easy to spot leaks in this type of roof because they usually show up on ceilings directly below the problem. Repairs don’t have to be a thing of beauty because the roof is not usually seen unless you’re above it.

If you see cracks in the roofing, our old friend asphalt roofing compound can usually solve the problem. Sometimes exposure to the heat from the sun can cause the top layer to blister. Sweep away the gravel over the area and slit the raised area. Use roofing compound to cover the slit and also force the cement into the slit. Lay down a bed of compound at least a couple of inches beyond the slit and apply a patch of roofing felt pushed into this bed of compound. Nail the patch in place using galvanized roofing nails. Then cover the entire patch with another bed of compound. Sweep the gravel back in place and your fix is done.

There’s no mystery about hardwoods. Oak, walnut, mahogany, teak and many more well-loved timbers are readily available if you want to use their rich, varied shades and patterns in your home.

Most hardwoods really are harder than softwoods – but not quite all; the two classifications are named for botanical, not practical reasons, and hardwoods themselves vary widely in strength, toughness and weather-resistance. Their denseness can make accurate work easier, but it can also blunt tools faster; and you’ll need to keep a sharp eye out for variable grain directions which make it hard to get an even surface with the plane.

Hardwoods do cost more, which is why softwoods are used for all rough house-carpentry. But your money buys a fascinating, inexhaustible variety of beautiful colors and grains. Once you have the confidence to work without paint to cover up your mistakes, and preferably with proper concealed joints rather than just screws and nails, you’ll want to use hardwoods for all their subtle decorative possibilities, varnishing or polishing them to bring these out.

There are thousands of hardwoods, many strangely named and hard to get. Here we show only those you’re most likely to find. But they give an idea of the tremendous range available. If your timber merchant shows you a piece of afzelia or jelutong, don’t turn your nose up: it may be just what you want.

Many hardwoods are often used as thin sheets of veneer, to give the appearance without the cost. Sticking veneer down by hand is a fairly specialised operation, unless you buy the ‘iron-on’ real-wood veneers which are available in some of the more common timbers. Ready-veneered chipboard, or plywood with a decorative top layer, is another option.

Hardwood sizes

You can’t buy hardwoods in standard sizes like nails, screws or even softwoods. Dimensions available depend on the supplier – and the wood. No-one can cut wide planks from narrow trees, or long straight pieces from short, twisted trees.

However, two groups of basic cross-sections are generally obtainable. Squarish pieces, for table and chair legs, panel edges, etc, can usually be found in sizes between 25 x 25mm (1 x 1 in) and 50 x 50mm (2 x 2in); and wider, flatter boards, eg, for wall cladding or joining edge-to-edge to make tabletops, from 6mm (1/4in) to 25mm (1 in) thick, and 150-300mm (6-12in) wide.

But visit your timber merchant, discuss your requirements and see what he’s got. Although you may have to consider alternative woods, he’ll often be willing to cut wood specifically to suit your measurements. In fact, since hardwoods come in so many different types and sizes, he may well have to. Be prepared, however, to modify your design if he suggests a more economical way of cutting the timber. His advice will save you money.

Beech, while not particularly decorative, is strong, and easy to work and finish because of its straight, close grain. Not durable enough for outdoor use, it is used in furniture, especially for chair-frames, and is sometimes given a pinkish color by steaming.

Oak can be red or, more commonly, white. Varieties of white oak come from Europe, America (underneath in the picture) and Japan. English oak, the hardest, strongest and most durable, was universally used for hundreds of years. Imported European oak is now commoner, while Japanese oak is the lightest in weight of the three. Oak is not richly colored, but it can have an attractive figure.

Mahogany is either American (the Honduras variety is on the right; Brazilian is also common) or African left – not the same species, but closely related and just as good. Mahogany is widely used for reproduction furniture. Its attraction lies in its rich color and lustre. Utile, another fine African wood, is very similar.

Ramin is a plain wood whose straight grain and even texture, like those of beech, make it very useful, though it is lighter and less sturdy. It splits quite easily. Mouldings are often cut from it, and it is used in furniture. Like beech, it is easily stained to match its surroundings.

Afrormosia is just one of many African hardwoods which are unfamiliar to most people but nevertheless widely used. Dense, richly colored and durable, it is more than just a substitute for teak, with which it is often compared: it is even stronger, and not greasy.

Elm resembles ash except for its rather darker color and often crooked grain – qualities which make it more ornamental but rather less generally useful. Devastation by Dutch elm disease has made it temporarily abundant in Britain, and varieties from Europe and Japan and also available.

Teak has long been celebrated for its great strength and extraordinary weather-resistance: it is ideal for all outdoor work. Its rich color has been in demand for furniture in recent years, though it is not cheap. Its greasiness presents difficulties in glueing and for some finishing processes.

Ash is another strong, pale wood like beech, but with the coarse, open texture of oak. Its exceptional toughness and straight grain suit it for bending and for such things as tool handles. However, it is not a good outdoor timber.

Walnut was widely used in English furniture of the Queen Anne period. True walnut realty comes from England (like the top piece in the picture) and other parts of Europe, as well as North America, but other similar woods are African (underneath), Queensland and New Guinea walnut. Its value lies in its depth and variety of color and its nicely varied grain.

Sycamore is one of the most attractive types of maple, and has a lustrous creamy color, sometimes nearly white. This, plus its compact grain and frequent rippling figure, give it a beauty of its own.

een Anne period. True walnut realty comes from England (like the top piece in the picture) and other parts of Europe, as well as North America, but other similar woods are African (underneath), Queensland and New Guinea walnut. Its value lies in its depth and variety of color and its nicely varied grain.

Preparing the base

The base for your paving must be firm and level. Firstly, clear all weeds, and loose materials from the area. Dig out any soft spots and fill the holes with firmer soil – or even broken rubble – then compact the surface thoroughly using a garden roller.

If you’re making a drive or other area that’s to be used for vehicular traffic you should excavate the site and lay a firm base of at least 100mm (4in) of clean, fine hardcore, which you should also compact thoroughly.

Areas that are only to be used for foot traffic, such as paths and patios, will probably only need a base of compacted soil, unless the surface is clay or soft, peat soil; here, the base should be the same as for drives.

The base must be at least 115mm (4 1/2in) below the level of the completed paved surface. The top surface, in turn, must be at least 150mm (6in) below the house damp-proof course (dpc) to prevent moisture rising in the walls or ram splashing up above the dpc.

Setting levels

Unless there’s a natural slope to the site you’ll have to excavate the base so that the finished surface will slope to one side – or at least away from the house walls – with a fall of about 1 in 40, to ensure efficient drainage of rainwater

To set the levels over the area of the base drive 300mm (1ft) long timber pegs into the ground at about 1 5m (5ft) intervals and set them at the correct level, taken from a ‘prime datum’, or fixed point of reference: two bricks below the dpc is adequate, for example. Use a long timber straightedge with a spirit level on the top edge to check that the pegs are set at the correct depth. Place a small wedge or ’shim’ of timber under one end of the spirit level to incorporate an adequate drainage fall.

Edge restraints

The edges of your concrete block paving are best retained, by the walls of your house garden walls or existing paving: simply setting them against earth won’t prevent eventual spreading of the blocks. If your dpc is lower than 150mm (6in), however, you must leave a 75mm (3in) wide channel between the wall and the paved surface to stop rainwater from splashing up and soaking the wall above the dpc In this case you’d need to fit an edge restraint.

If there isn’t a natural or existing edge restraint you’ll have to install permanent formwork. Precast concrete, concrete path edging stones or a row of bricks on edge can be used, bedded in a strip of concrete, or you could use creosoted lengths of 38mm (1 1/2in) thick softwood screwed or nailed to stout 50 x 50mm (2 x 2in) pegs driven into the ground outside the area you’re going to pave. The depth of these battens should equal the thickness of the blocks plus the sand bed.

The sand bed

When you’ve levelled and compacted the sub-base and have set up the formwork you can lay the bedding sand directly on top. For this you’ll need sharp (concreting) sand. As a rough guide to amounts, 1 tonne of sand is ample for 10 sq metres (110sq ft) of paving.

Although the final thickness of the sand bed should be 50mm (2in) you’ll have to add more to allow for compaction of the paving.

You’ll find it more convenient to work if you divide the load of sand into separate piles and position them at intervals along the site, away from the point at which you want to start laying the blocks.

Spread out the sand evenly over the sub-base, between the edge restraints, using a garden rake, then ’screed’ or smooth the surface to the correct level with a straight-edged length of timber that spans the width of the area you’re paving. The top of the sand bed should be levelled to about 50mm (2in) below the finished paving (and therefore the level of the edge restraint) when you’re using 65mm (21/2in) thick blocks, and about 45mm (13/4in) below when using 60mm (21/4in) thick blocks. To allow for this depth you can cut notches in the straightedge to form ‘arms’ that rest on the formwork; the body of this ’spreader’ should be the thickness of the blocks plus about 15mm (1/2in) for compaction of sand.

Where you’re using an existing wall or fence as an edge restraint you’ll have to set a temporary screeding batten on the sub-base, which you can remove after levelling. Fill the groove left by the batten with more sand and level the surface.

Screed the sand in areas only about 2m (6ft) ahead of the blocklaying for convenience and avoid walking on the sand during or after you’ve levelled the surface.

Cutting the blocks

Although you should use whole blocks wherever possible for maximum strength, you’ll certainly need to cut some to size and shape where the paved area contains obstacles such as drains or inspection covers, and where it meets the edge restraints.

It’s possible to mark the individual blocks to size and cut them using a club hammer and bolster chisel but you can hire a hydraulic stone splitter or guillotine, which will make the job much easier. Keep the guillotine close to the edge of the paving for convenience. If you must stand it on the paving, rest it on a board so you don’t mark or upset any of the blocks. If you use a hammer and chisel be sure to wear gloves and goggles to protect your eyes from flying fragments.

Compacting the blocks

When you’ve laid a large enough area of blocks bed them firmly into the sand using a plate vibrator fitted with a rubber sole plate. This will settle the blocks into place and force sand up into the joints, without damaging them.

The plate vibrator should have a plate area of 0.2 to 0.3sq metres (2 to 3sq ft), a frequency of 75 to 100 Hz and a centrifugal force of 7 to 20kN, to ensure the blocks will be bedded correctly. Most machines of this type will fit easily into the boot of a car.

Make two or three passes over the paving with the plate vibrator in order to bed the blocks to the correct level, but avoid lingering in one place or you might sink them too low. Also, don’t take the machine closer than 1 m (3ft) to the unrestrained edge you’re laying or you’re likely to form a dip in the surface.

Finishing the paving

Finally, simply brush sand onto the paved surface and make a few more passes with the plate vibrator to force the sand down between the blocks.

If you’re laying a very small, mainly decorative, area of blocks that won’t be used for vehicles – a narrow border around a flower bed, for instance – it’s acceptable to lay them without using the vibrator, although the job is more laborious and the results won’t be as durable

Instead lay a thinner sand bed, moistened with water from a watering can fitted with a fine rose, and level and compact this with a straight-edged tamping board. Lay the blocks as previously described but bed each as level as possible using a wooden mallet with an offcut of timber just larger than the block. Water more sand into the joint, again using your watering can, to complete the area of paving.

Immediately you’ve laid the blocks and vibrated them into place, your paved area is ready for use. Inspect the surface after a few months to make sure there aren’t any areas that have subsided fractionally. If there are uneven areas you may simply be able to lever out the relevant blocks and re-bed them on more sand.

1. Vibrate the blocks into the sand bed with a hired plate vibrator. You can avoid marking the blocks by running the machine over some old carpet.

2. After the first passes with the plate vibrator, scatter sand over the surface and brush it well into the gaps between the individual blocks.

3. Run the plate vibrator over the surface again, making two or three passes over each area, to compact the sand between the blocks thoroughly.

4. Finish off the paving by brushing off excess sand with a soft-bristled broom, taking care not to brush out the joints. The paving is ready for immediate use.

Paving irregular areas

Because of the small size of the blocks, you can use them to good effect to pave irregularly-shaped areas. Where necessary the blocks can be cut at an angle to form neat edges, and circles can be formed by laying the blocks with wedge-shaped joints instead of parallel-sided ones – rather like forming a brick arch. To achieve perfect curves, lay the blocks using a string line attached to a peg at the centre of the curve, so that by holding the string taut you can align them accurately.

Coping with steps

If you have used blocks for a path or patio, you may want to link these areas with steps paved in the same way. Because of the small size of the blocks it is vital to bed them on mortar rather than on sand, particularly at the edges of the treads. You can still use sand to fill the joints between the blocks and so maintain the overall sense of unity.

Building with blocks
Similarly, you may want to build dwarf walls at the edges of your paved area, and while you could use any garden walling blocks for this there is nothing to stop you using two or three courses of paving blocks instead. The rectangular ones are laid just like bricks with pointed mortar joints between, but the interlocking and fishtail types can also be built up into walls if they are overlapped by half a block and aligned carefully.

cks and so maintain the overall sense of unity.

Building with blocks
Similarly, you may want to build dwarf walls at the edges of your paved area, and while you could use any garden walling blocks for this there is nothing to stop you using two or three courses of paving blocks instead. The rectangular ones are laid just like bricks with pointed mortar joints between, but the interlocking and fishtail types can also be built up into walls if they are overlapped by half a block and aligned careful