RICS Chartered Surveyors in Halifax

Gritstone, Elland flag and a wall that has to breathe

Geologically the parish splits in two. The high ground on both sides of the valley belongs to the coarse sandstones of the Millstone Grit Group, and it is from those beds that most of the walling stone came. Drop east down the Calder towards Elland and Brighouse and the sequence changes to Coal Measures, which is where the Elland Flag was won: a fine, evenly bedded sandstone that splits cleanly and was used across the district for roofing flags, paving and cills. Knowing which of the two you are standing in front of changes the advice, because the flags and the walling stone weather at different rates and want different treatment.

The more important fact about a Halifax wall is not the stone, though. It is the exposure. Calderdale sits high, open and directly in the path of weather coming in off the Atlantic, and its west and south west facing elevations take wind driven rain in a quantity that most of the country never sees. A solid stone wall has no cavity and no barrier inside it. It copes with rain purely by being thick enough that water penetrating the outer face never quite reaches the inner one before the weather turns and the wall dries back out. That is a balance, and it works for two hundred years until somebody upsets it.

Upsetting it is easy. Seal the outside with an impervious coating or a hard pointing mix and the water that does get in cannot get back out. Line the inside with an impermeable render or a plastic membrane and you have moved the wet face inward instead of removing it. Replace deep eaves with a tidy flush detail, lose the projecting cills and copings, or let a downpipe discharge onto the stone, and you have concentrated in one spot what the elevation used to shed across its whole face. A very large proportion of the damp we are called to diagnose in this town is not a fault of the original building at all. It is the residue of a well meant repair.

The traditional answers here are worth knowing about because they are still the right answers. Lime render and harling on the most exposed gable. Vertical stone slate hanging on a west wall, which you can still see on older Calderdale property and which is simply a rain screen built two centuries before anyone used that phrase. Generous overhangs, proper throats under cills, and lime pointing that is softer than the stone around it. When we recommend work, it is work in that tradition, not a coating that promises to keep water out of a wall that has always been designed to let a little in and give it back.

The top-and-bottom house: two homes in one block of stone

The building type that defines Halifax is the top-and-bottom house, sometimes called an over dwelling and under dwelling. The ground was too steep to build outwards, so it was built upwards and sliced horizontally. One dwelling occupies the lower floors and is entered from the lower street or the fold behind it. A completely separate dwelling sits above it and is entered from the higher street, often at what is the first or second floor of the block. Neither has a stair to the other. They are two addresses, two council tax bills and frequently two freeholds, inside one structure. You find them all over the town and up the valley at Sowerby Bridge, Hebden Bridge and Todmorden.

The ownership consequences are the part buyers are least prepared for. The floor between the two dwellings is simultaneously one owner's floor and the other owner's ceiling, and the joists in it are usually built into walls that belong to both. Where any part of one dwelling oversails the other, you have a flying freehold, which means part of what you are buying sits above land you do not own. There is often no lease and therefore no standing mechanism to compel either party to repair anything, no service charge, and no schedule saying who maintains the roof that keeps the rain off both of you. Your solicitor will want to establish exactly where the boundary runs in three dimensions, what covenants exist, whether there are mutual rights of support and shelter, and whether an indemnity policy is appropriate. Our job is to tell them precisely which parts of the fabric are shared so that they know what to ask.

The physical consequences fall mostly on the lower dwelling. Buried on two or sometimes three sides by the hillside, it is a cellar dwelling in all but name. The rear and side walls are in permanent contact with wet ground, the only natural light and ventilation arrive from one elevation, and the joist ends of the party floor bear into walls that never fully dry. That combination is the single most reliable place in Halifax to find wet rot, and it is where dry rot establishes when a void has been sealed up. On top of that, fire separation and sound insulation between two dwellings stacked like this are frequently nothing more than the original lath, plaster and floorboards.

So we survey them differently. Where access can be arranged we ask to see both dwellings, because a defect in the upper one is very often the cause of the symptom in the lower one, and a leaking upper bathroom or a blocked upper gutter will show up as somebody else's damp ceiling. We take readings at the joist ends of the party floor specifically, look for any evidence of the original ventilation to the lower dwelling being blocked, read the title plan alongside what we can see, and, with the owner's permission, lift a board where the readings tell us to. A report that treats a top-and-bottom house as an ordinary terrace has missed the entire point of the building.

Defects we see most in Halifax homes

Because so much of the work here begins with moisture, the recurring list is weighted that way. These are the findings our Halifax reports carry most often.

• Penetrating damp on west and south west facing gables, heaviest at first floor and around openings, that worsens after a spell of westerly gales rather than after wet ground, which is how you tell it apart from anything rising.
• Injected chemical damp proof courses and sand cement tanking render installed in lower dwellings, which do not stop the moisture but relocate it to the first unprotected surface above the treated zone.
• Wet rot in the joist ends of the party floor between a top-and-bottom pair, where the bearing is buried in an external wall that is permanently damp.
• Dry rot behind tanked linings, under cellar stairs and in sealed voids, with mycelium tracking through the masonry well beyond the timber it started in.
• Common furniture beetle in damp softwood cellar joists, stair strings and floorboards, with live flight holes and frass where the moisture content has stayed high enough to sustain it.
• Condensation and black mould in rooms where the flue was blocked and the windows sealed at the same time, so the last two routes out for water vapour were removed together.
• Shared gutters, hopper heads and downpipes on stepped terraces discharging directly against stonework, and rainwater goods on a neighbour's side of a boundary that nobody accepts responsibility for.
• Stone flag ground floors bedded straight on earth, later sealed with an impervious covering or a screed, pushing ground moisture out to the wall bases at the edges of the room.

Buying in Halifax: flood history, access and the timetable

Calderdale has a serious flood history and it is recent. The valley flooded in 2012 and again on Boxing Day 2015, with Hebden Bridge, Mytholmroyd, Sowerby Bridge, Todmorden, Elland and Brighouse all badly affected, and the memory of that is priced into insurance and into buyers' nerves. If you are looking at valley floor property, the report examines the quality of any reinstatement as closely as the original fabric, because a flooded house that was dried and replastered too quickly will hold moisture in the wall base for years. We also look at whether any resilience measures were fitted and whether they were fitted competently.

If you are buying up on the hillside, the risk is real but it is a different one. You are not exposed to the river. You are exposed to surface water arriving off the road above you, to culverted becks including the Hebble Brook that run beneath yards and property through the centre of town, and to a neighbour's drainage discharging onto your ground because that is where gravity takes it. We say which of these applies to the property in front of us, rather than quoting a generic flood paragraph, and we tell your solicitor what to search for.

On access, tell the agent we need the lower rooms unlocked, the loft hatch free, the cellar and any under dwelling open, and the yard or fold at the back reachable. On a stepped site the back of a building is where the answers are, and it is routinely the part nobody thinks to unlock. If you are buying one half of a top-and-bottom, ask early whether the occupier of the other half will allow a look, because that access is often the difference between a diagnosis and an assumption. Where a roof or a tall gable cannot be seen safely from ground level, we will offer a drone roof survey rather than write it off as not inspected.

The town has a good deal of designated fabric, and it changes what repairs are permissible. The Piece Hall and the streets around it, Dean Clough, the Wainhouse Tower area, Savile Park and Heath, and the model villages at Akroydon and Copley all sit within conservation areas or contain listed buildings. Where that applies, the report says so and identifies any alteration that looks as though it needed consent, because an unauthorised change becomes your responsibility on completion. Instruct as soon as your offer is accepted, ring the surveyor after the visit to talk it through, and use the written report as the basis of a renegotiation rather than a worry.

Other surveys and valuations we carry out across Calderdale

A timber and damp report is often instructed on its own, but just as often it follows something else. We carry out Level 2 Homebuyer Surveys on the more conventional stock around the town and Level 3 Building Surveys on older, altered, stacked or stone built property, and where either raises a moisture question we can return and investigate it properly. We also provide structural engineer's reports where a wall is bulging or a stepped boundary is moving, drone roof surveys on tall valley terraces and mill buildings, boundary and party wall dispute reports, asbestos surveys, EPCs and fire risk assessments on converted premises. For owners and executors we prepare probate valuations, matrimonial valuations, Help to Buy valuations, private valuations and building insurance reinstatement valuations.

We cover the whole of the district from the same base, so Brighouse, Elland, Sowerby Bridge, Hebden Bridge, Todmorden and Ripponden are ordinary ground for us and the travel is inside the fixed fee we quote. On the commercial side we survey shops, offices, mills and industrial units, prepare schedules of condition before a lease begins, advise on dilapidations at the end of one and carry out commercial valuations and rent reviews. The full list is on our Types of Survey page. If you are not certain which report answers your question, describe the property and the symptom on the phone and we will tell you.