Buying A House? How To Read The Roof First

Key takeaways

• The loft answers the questions the outside cannot, and access is easier during a viewing than afterwards.
• What is under the covering matters more than what is on top of it.
• Compare the roof against the neighbours, since houses built together age together.
• Any extension, conversion or later addition brings junctions that are the most likely leak points.
• Findings become negotiating position, but only if you have them before the offer.

Why do this yourself when a survey is coming

Three reasons. First, timing: a survey happens after an offer has been accepted, by which point you are emotionally and often financially committed, whereas a viewing happens while you still have complete freedom. Second, access: a standard survey is generally non intrusive and a surveyor may look into the loft from the hatch or not at all, whereas you can ask the seller to let you look properly. Third, specificity: survey reports are cautious by design and frequently recommend further investigation rather than saying what they think, which is professionally sensible and not much use for deciding whether to offer.

The outside, from across the road

Before going in, cross the road and look at the whole roof plane. Check the ridge line against the sky for gaps, displaced tiles or a dip. Look along both gable edges. Scan the slopes for missing units, tiles sitting proud, or a wavy course line. Look at the chimney for split mortar, leaning pots and vegetation. Then look at the neighbours, which is the most useful comparison available: if the house you are viewing has visibly older or more degraded covering than the two either side, that is a strong signal, and if it has obviously been recovered when the neighbours have not, that is a different and better one.

The loft, which is the whole point

Ask to look in the loft and take a torch, though the useful part is done with the light off. Once your eyes adjust, look for daylight through the slope, which on a modern roof should not be visible at all. Look at the underside: a modern breathable membrane means recent work, bitumen felt means mid twentieth century and probably tired, and nothing at all means an older roof where the covering is the only barrier. Look at the timbers for dark run marks and staining, at the insulation for damp patches, and at the whole space for a musty smell that suggests a persistent moisture problem.

What the loft tells you about money

The underlay question is the one that most affects cost. A roof with a functioning membrane can lose a tile and be fine until somebody replaces it. A roof with perished felt or no underlay has no margin, and every gap is a live leak in driven rain. Combined with the state of the fixings, visible as rusted nail points, and the battens, which can be pressed with a finger where reachable, you can form a reasonable view of whether this roof needs a strip and relay within the next several years. That is the single largest roofing number a homeowner ever faces, and it is knowable at a viewing.

The junctions and the additions

Look at what has been added to the building over its life, because that is where roofs leak. An extension creates an abutment against the original wall. A conservatory creates another. A converted loft brings dormer cheeks and roof window flashings into the picture. A porch, a bay and a garage each carry their own small roof. Every one of those is a junction detailed by whoever did that work, at whatever standard, and collectively they cause a disproportionate share of problems. From an upstairs window you can usually see the flat roofs of extensions and bays, which are otherwise invisible and are frequently the worst thing about a house.

The inside evidence

Take each first floor room in turn and give the ceiling and the head of every outside wall a proper look in daylight. Fresh paint in one room only, particularly on a ceiling, is worth noticing, and it is entirely reasonable to ask about it. Look in the corners of bedrooms for mould, around any roof window for staining, and at the wall above a bay. Look behind furniture where you can. None of this is intrusive and all of it is visible during a normal viewing. A seller who has recently painted a ceiling may simply be presenting the house well, and may also be covering something, and the loft above that room usually answers which.

Questions worth asking the seller

Ask directly when the roof was last worked on and what was done, and whether they have paperwork. Ask whether there has ever been a leak and where. Ask about the loft insulation and whether anything has been done to the roof space. Ask whether the extension or conversion had building control involvement. Sellers are required to answer questions honestly in the formal enquiries process later, and asking early gives you the answer before you are committed. It also tells you something about how the house has been maintained, since an owner who can produce an invoice for gutter work has probably looked after other things too.

The property specific things to check

Some house types carry known issues worth checking directly. On a terrace, ask about the shared chimney stack and look at the state of it, since responsibility is joint. On an older property, ask whether the roof is original. On anything with a stone or heavy covering, look at the ridge line for distortion. On a modern house, look at the dry verge caps and ridge system for missing or lifted components. And on any property with a flat roof of any size, establish its age, since that is a defined replacement cost arriving on a defined schedule.

Getting a roofer to look before you commit

For a purchase of any significance, having a roofer inspect before exchange is inexpensive relative to the transaction and answers the question definitively. It is more useful than the roof section of a general survey because it is specific and quantified: a roofer will tell you what it needs and roughly what that costs, which is exactly what a surveyor typically will not. Sellers and agents are usually willing to allow access for this if asked reasonably, particularly once an offer is agreed. If a seller refuses access to the loft or to a roofer, that refusal is itself information.

Using what you find

Findings translate into either a renegotiation or a decision to walk, and both need the information early. A quantified figure from a roofer is far more persuasive than a survey's recommendation for further investigation, because it is specific and the seller can check it. Whether you renegotiate on the roof depends on the market and on how the price was set, and a roof at the end of its life on a property priced as though it were sound is a legitimate basis for a conversation. What removes that option entirely is discovering it after completion, which is what happens when nobody looks in the loft.

The short version to take with you

Look at the whole roof from across the road and compare it with the neighbours. Ask to go in the loft, turn the light off, and look for daylight, underlay type, staining and damp insulation. Look at every junction and every addition. Check upstairs ceilings and the tops of walls, and look at bay and extension roofs from an upstairs window. Ask when the roof was last touched and for the paperwork. If anything concerns you, get a roofer in before exchange. That sequence takes twenty minutes at the viewing and can protect an amount of money entirely out of proportion to the effort involved. It is also the part of a viewing that nobody else will do for you, since the agent is acting for the seller and the surveyor has not yet been instructed. Nobody in that room has an interest in you understanding the roof except you.

Frequently Asked Questions

Will the survey not tell me about the roof?

Partly, and later than you want it. A survey happens after an offer is accepted, is generally non intrusive, and is worded cautiously, often recommending further investigation rather than reaching a conclusion. A viewing lets you look in the loft yourself, while you still have complete freedom to walk away.

What should I look for in the loft?

With the light off and your eyes adjusted: daylight through the slope, which should not be visible on a modern roof; what the underlay is, since a breathable membrane, perished felt and nothing at all mean very different things; staining on the timbers; damp insulation; and a persistent musty smell.

Why does the underlay matter so much?

Because it determines whether the roof has any margin. With a functioning membrane, a lost tile is an inconvenience. With perished felt or no underlay, every gap admits water in driven rain. Combined with the state of fixings and battens, it indicates whether a strip and relay is coming within a few years.

Should I get a roofer to look before I buy?

For any significant purchase, yes. It costs little against the transaction and produces something a survey usually will not: a specific description of what the roof needs and roughly what it costs. Sellers will generally allow access if asked reasonably, and a refusal is itself informative.

What should I ask the seller?

When the roof was last worked on and what was done, whether there is paperwork, whether there has ever been a leak and where, what has been done in the loft, and whether any extension or conversion had building control involvement. Asking early gets answers before you are committed.

Can I renegotiate on the roof?

It depends on the market and how the price was set, and a quantified figure from a roofer is far more persuasive than a survey recommending further investigation. What removes the option entirely is finding out after completion, which is what happens when nobody looks in the loft.