How to Keep Your Renovation on Track

Starting a renovation project is hugely exciting. However, a lack of awareness about the hidden problems that commonly go hand-in-hand with older properties can mean the initial excitement quickly turns to stress, says Natasha Brinsmead

…and avoid the pitfalls which may put a spanner in your schedule

PROJECT ADVICE In-depth, need-to-know building and project management advice from leading experts

Breathing life back into an old building in order to call it home is one of the most satisfying things you can do. However, it can also be one of the most stressful, not to mention a financial drain — to be forewarned is to be forearmed and knowing what might lie in store can ease the pressure.

While some of the renovation work will be immediately obvious – rotten windows, dated kitchens and bathrooms, for example – other issues are likely to be hidden from view, and perhaps not picked up on during a survey either, waiting to disrupt your wellplanned schedule. Identifying these issues early on will help you keep your renovation project on track.

The Importance of a Survey

A full structural survey should reveal structural issues, but it is amazing how many people don’t have one. Don’t rely on mortgage valuations alone.

There are various types of survey available, from the RICS Home Condition Report to the next level RICS Homebuyer Reports and more comprehensive building surveys. A HomeBuyer Report is a popular choice, which should highlight problems such as subsidence and damp. However, it tends to be less thorough than a build- ing survey, where floorboards are lifted, attics explored and so on. In the case of a period property, a building survey is best. Surveys cost from £500 up to around £1,500, depending on the survey and the value of the house, but they are a worthwhile investment.

Structural Movement

The word ‘subsidence’ can cause huge panic among renovators (and mortgage lenders), but the fact is, all buildings move, and old properties, usually built with shallower foundations, move more than newer ones, particularly in areas of clay soil. Some

“Although the first thought is often underpinning... this should be reserved as a last resort”

movement is harmless, but identifying its cause early on, and pricing up the remedy, will avoid any nasty surprises and delays.

One of the most common culprits is trees. They can cause the ground under the foundations to shrink as they extract moisture, particularly in long periods of draught and in clay soils. The wall above then drops, causing cracks to appear.

Whatever the cause, the main issue is whether the movement is ‘ historic’ (i.e. no longer happening) or ‘progressive’ and likely to continue.

The costs involved in remedying this problem depend on its cause and although the first thought is often underpinning, this is not always necessary. Underpinning typically involves excavating the ground beneath the sunken walls and pumping in concrete. This should be reserved as a last resort — it is expensive and can cause further problems in old properties.

If trees are causing the subsidence, there are two main options: to remove the tree or to heavily prune it. This won’t work in all cases — sometimes cutting down a tree can actually cause the ground to swell, and if the tree has a Tree Preservation Order (TPO) on it you may not be allowed anyway.

Installing root barriers is an alternative. All these solutions are considerably cheaper than underpinning — the average cost of which, for a typical house, is from £10,000-£15,000.

Other causes can be shallow foundations — if you suspect this, look out for cracks that extend below damp-proof course level. Diagonal cracks that increase in width as they go up the building are another tell-tale sign.

Finally, leaking drains are a common culprit and if fixed, the problem is often remedied.

Damp

Although all renovators should be, and usually are, prepared for some damp, the key to preventing it causing delays in your schedule is getting to the root of the problem quickly.

Rotten Joists

No matter how you discover rotten joists (often during a rewire or plumbing job), you need to put them right and find out what caused it to happen.

There are several possible causes, including leaking pipes, raised ground levels around the house and blocked air vents. All cause damp which, in turn, causes timber joists to rot. It could also be attributed to dry rot or a beetle infestation — both of which are best dealt with by specialists. Once the cause is eliminated, the rotten timber will need to be cut away and replaced.

Modern interventions are one of the most common causes of damp in old buildings. Concrete floors and mortar, for example, can restrict the building’s ability to breathe — unlike the limebased products that would originally have been used.

Similarly, sealing up houses with double glazing and the like means old houses are not ventilated in the way they originally were, so condensation occurs (see page 155 for more).

If there is damp along the base of your walls, you may find that debris has built up outside or that the ground level is higher than the DPC, in which case, digging out the surrounding ground, and sometimes laying a French drain in waterlogged areas, will solve the problem.

Faulty Roof

The downfall of many a well-planned budget. While renovators are usually prepared for re-roofing, what they often fail to identify is the damage that can lie beneath, hiding away waiting to hold up the project and expand the costs involved. Look out for leaks inside the house, along with broken or

“All renovators should be prepared for damp... the key is getting to the root of the problem quickly”

Dry Rot

A quickly. fungus Dry that rot will loves destroy moist, timber poorly very ventilated conditions and is usually found in the roofspace or under timber floorboards. Dry rot is easy to identify. Spores send out fungal strands along the timber and through/along any wall. These strands can become quite dense and form a cotton wool-like mass. The first sign is often its distinctive musty smell when you lift a floorboard or even just the carpet. Getting rid of it may cost around £1,000 for treatment by a specialist firm, with additional repair costs for damaged areas. The best way to prevent a recurrence is to improve ventilation and eradicate any damp.

Wet Rot

This is the natural decay of timber, exacerbated by high levels of moisture. Timber suffering from wet rot will feel spongy and look darker than surrounding timber. When dry, the timber will crumble into fine particles. The cost of solving it depends on how damaged the timber is, but the problem will not return if you solve damp problems in the house and improve ventilation.

slipped roof tiles, absent or broken flashings, damaged or missing underfelt and worn pointing on verges.

Although these do not always point to rotten roof timbers, if they have been left in this state for long enough, it is likely that damage will have occurred and they will need replacing before any re-roofing takes place.

This is a common cause of delays in extension projects. Additions to the older part of the building cannot begin until the existing areas of roof are made good. Replacing a few roof tiles and repointing the verges is a relatively quick job. However, if the damage is extensive, then it may be cheaper to remove the old roof and lay a new one. Replacing the entire roof over a typical three bedroom terraced house may cost upwards of £4,000.

Rewiring

Overlooking the need for a complete rewire is a common cause of renovation delays, so ascertain whether one is going to be needed early on. Obvious signs to look out for are dated switches and sockets, and damaged cables.

A rewire is a messy, disruptive job. Floorboards will be lifted to allow access for cabling and lots of dust is standard while walls are chased out. Replastering will also be required and your electrician will need access to all areas of the property at all times.

Expect to pay from £4,000 for a complete house rewire.

No Sub Floor

A complete lack of sub floor is a common problem that often lies undiscovered, waiting to cause delays.

Quarry tiles and parquet, as well as flagstones, were frequently laid on nothing more than earth, ash or sand. While this is not a huge problem, it makes for a cold floor underfoot as there is rarely any insulation. This can mean damp leaches up through the floor, particularly if a thick rug or carpet is laid over it. These floors were designed to be ‘ breathable’ and to ab- sorb and evaporate moisture from the whole surface area with no damage to the materials used. Problems only tend to occur when they are covered over with a non-breathable material, or an unsuitable insulation is laid beneath them.

One solution is to take up the floor covering and dig out the floor to a level that will allow for insulation, a dampproof membrane, concrete and your new floor covering.

The first problem is that using concrete at all can restrict the floor’s ability to breathe. The second issue is that the insulation materials you use need to be able to withstand the weight of the concrete slab or screed being laid on top, limiting the choices of insulation to those that are basically impervious to air and moisture. These types of insulation materials will disrupt the moisture balance in quarry tiles, flagstones or brick.

Taking up your floor and relaying it on a concrete sub floor with a damp-proof membrane can also cause salts within the old floor to come to the surface and these, in turn, can absorb moisture from the air and result in damp.

The good news is that there are methods for insulating under these floor coverings that won’t interfere with their ability to breathe — namely limecrete. Limecrete is a mix of natural hydraulic lime and sharp sand and deals with naturally occuring moisture well. Recycled foam glass beads are often used as a breathable insulating base. Both timber floors and stone can be laid over it — providing lime-based adhesive and grout are used.

Finally, simply using a breathable natural floor covering, such as coir, will make things more comfortable underfloor and shouldn’t interfere with the floor’s ability to harmlessly shed moisture as it was always intended to do.

Forgotten Fees and Incomplete Quotes

It is all well and good costing up what needs to be spent on the fabric of your house, but don’t forget to budget for professional fees too.

Architects, structural engineers, Building Regs and planning permission all add significantly to costs.

Go through all your quotes from builders and trades with a fine-tooth comb in order to establish what is and isn’t included — you are trying to avoid any nasty surprises here.

For a large-scale renovation, the total amount of professional fees, including architects or designers and structural engineers, can easily come to well over £10,000. H