How to check whether a new roof has been installed properly

When a new roof has just been completed, most homeowners understandably look at the tiles first. But the visible covering is only one part of the job. The important question is whether the roof has been rebuilt as a complete, weatherproof system — and whether the details that stop future leaks have been finished properly.

The best checks can be made from the ground, from the loft and from the paperwork. You should never need to climb onto a roof to inspect the work.

1. Start with the written specification

Before the work starts, the quote should tell you what is actually being renewed. For a full pitched re-roof, look for clear wording about:

• Removal of the existing tiles, battens and old underlay where the quote says the roof is being stripped back
• A vapour-permeable or breathable membrane
• New treated, graded battens set to the correct gauge for the chosen tile
• Eaves protection or felt support trays
• The fixing method for ridges, hips and verges
• Leadwork, valleys and abutments where they are part of the roof
• Insulation and Building Regulations certification where required

A quote that only says “re-tile” may describe a very different job from a roof stripped back to the rafters. Check the specification before the scaffold goes up, not after the tiles have been delivered.

2. Was it stripped back, or simply re-covered?

If you have paid for a full re-roof with new membrane and battens, the old roof covering should not simply be taken off and put back over the existing roof build-up. Removing the old materials allows the roof structure, eaves and junctions to be inspected properly.

Ask for photographs from the strip stage. A good roofer should be able to show you the roof back to the rafters, any repairs that were needed and the condition of the timbers before the new covering went on.

3. Look at the membrane and battens

The membrane should form a continuous layer beneath the tiles. It should be correctly lapped, secured and supported at the eaves so water running down it reaches the gutter rather than finding its way behind the fascia.

Battens should be straight, treated and spaced to the manufacturer's gauge for the tile selected. This is one of the most important hidden stages of a re-roof because it controls how the tiles sit, overlap and shed water.

• The membrane is continuous and properly formed around roof details
• The laps and cut edges follow the roofing system being used
• Battens run consistently and are securely fixed
• The batten gauge matches the manufacturer's requirements for the chosen tile
• Valleys, chimneys and abutments have been cut and detailed neatly

4. Check the eaves and gutter discharge

Many roof problems begin at the eaves. From the ground, the tiles should finish in a consistent line and discharge into the gutter. In the loft, the membrane should not be left hanging into the roof space or directing water behind the fascia.

• The membrane and eaves support are properly formed into the guttering
• Tiles have a consistent overhang and are not dropping behind the gutter
• The guttering is clear of tile fragments, old mortar and membrane
• New fascias and gutters, if included, are secure and correctly aligned

5. Check the ridge, hips and verges

Ridges, hips and verges take a lot of wind exposure. If the quote promised a dry-fix system, the tiles should be mechanically fixed with the correct compatible components rather than relying on a smear of mortar. Mortar bedding can be appropriate in some situations, but the finished method should match the agreed specification.

• Ridge and hip tiles are straight and evenly aligned
• The fixing method matches the quote
• Dry-fix components are secured where a dry-fix system was specified
• Verges are neat, secure and free from obvious gaps
• There are no cracked tiles, loose mortar joints or unfinished edges

6. Look closely at chimneys, valleys and abutments

A roof can look excellent from the road while the difficult junctions are still poorly finished. Lead flashings should be properly dressed and fixed, valleys should be clean and weathered, and abutments should not rely on sealant alone as the main weatherproofing detail.

Ask for close-up photographs of chimneys, roof-to-wall junctions and valleys. Where two properties meet, ask how the party-wall junction or bonding gutter has been formed and how both sides are covered by the guarantee.

7. Check the tiles are straight and undamaged

Stand back and look across the roof rather than only looking upwards from the front door. The tile courses should follow the lines of the roof, with a consistent appearance from one side to the other.

• No cracked, slipped or visibly damaged tiles at handover
• Courses look straight rather than wandering across the roof
• Cuts around valleys, chimneys and roof windows are secure and neatly finished
• The tile matches the product and colour agreed in the quote
• Ridge and edge lines are straight and tidy

8. Check loft insulation and ventilation

If insulation has been topped up, it should not be pushed tightly into the eaves in a way that blocks the airflow. A dry, healthy loft needs both insulation and ventilation, particularly around the roof edges.

Ask what insulation work was carried out and whether it formed part of the Building Regulations approval or certification for the project. It is better to have this explained at handover than to discover later that the loft has been packed full but the eaves ventilation has been blocked.

9. Ask for the paperwork

A finished roof should come with a clear handover, not just a request for the final payment. Keep copies of:

• The written workmanship guarantee
• Any insurance-backed guarantee included in the quote
• Building Regulations completion or certification documents where required
• Manufacturer warranties for tiles and other specified products
• Photographs of the concealed stages and difficult junctions
• A written note of any agreed exclusions, follow-up work or remedials

Warning signs worth questioning

• The job was sold as a full re-roof but nobody can confirm whether the old felt and battens were removed
• The ridge, hip or verge finish is different from the method described in the quote with no explanation
• Chimneys, valleys or roof-to-wall junctions appear to be weathered with sealant alone
• The gutters contain a large amount of tile, mortar or old roof debris after completion
• There are loose tiles, water ingress or unexplained draughts after the job is finished
• The roofer cannot clearly explain which guarantees and certificates you are receiving

What we show at handover

At WeatherTech, we use photographs to show the roof at the stages you cannot see once the tiles are on: the strip-back, the membrane and battens, the eaves, the junctions and the finished covering. The point is simple — you should be able to understand what has been done without having to climb a ladder.

If you are comparing quotes, ask every roofer the same questions. The cheapest price can look attractive until you discover it covers a different standard of work. A proper roof is not just new tiles; it is the structure, membrane, battens, eaves, junctions, ventilation and paperwork working together.