How is commercial roofing priced - per square metre or as a fixed project cost?

Most commercial roofing contractors price by the square metre for material and labour, then add a fixed allowance for access equipment, drainage work and any deck repairs found during stripping. For flat roof replacement in the Newmarket area, expect roughly £70 to £120 per square metre for torch-on felt and £80 to £140 per square metre for EPDM rubber, with larger roof areas typically attracting a lower per-metre rate. Always ask for the deck repair rate to be specified separately so you are not surprised if the boards beneath the old membrane need replacing.

How do I know if my commercial roof needs a full replacement or just a repair?

A repair is appropriate when the membrane or covering is broadly sound and the failure is localised to a specific area such as a flashing, a single split or a blocked outlet. Once a flat roof membrane shows widespread crazing, multiple blisters or perished laps across the whole surface, patching becomes uneconomical because new failures appear faster than old ones are fixed. A proper roof survey, which involves inspecting the membrane, drainage, flashings and any penetrations, will give you a clear picture of whether repair or replacement is the better investment.

Can commercial roofing work be carried out without closing my business?

In most cases, yes. Flat roof replacement on a commercial building is done from above, so the business beneath can usually continue operating normally. Work that involves cutting through the deck, removing rooflights or working near open edges above occupied areas requires more careful planning and may need to be phased or done outside business hours. Discuss this at the survey stage so the contractor can factor access requirements into the programme and the price.

Chimney Rebuilds in Lakenheath

Chimney Rebuilds · Lakenheath

Expert Chimney Rebuilds
in Lakenheath

Choosing the Right Materials for a Chimney Rebuild

A chimney rebuild is not simply a case of taking down what is there and putting it back up again. The materials you choose - bricks, mortar, flaunching mix, lead, pot type - all affect how well the stack performs and how long it holds up. Choosing the wrong materials, even with good workmanship, can create problems within a few years. This page sets out your main options honestly, including the trade-offs involved.

Bricks: Matching What Is There or Upgrading

Where the original brickwork is still largely sound, we try to source replacement bricks that match in colour, texture, and size. This matters for appearance, particularly on a chimney visible from the road, but also because mismatched bricks of different densities and absorption rates can behave differently under frost - creating new stress points at the joint between old and new courses.

For a full rebuild, the options are:

Reclaimed bricks. Salvaged from demolition, these often match older properties well in colour and texture. The honest downside is variability - reclaimed bricks differ in quality and porosity. Some are excellent; others are already frost-damaged and will fail again in a few years. A good roofer inspects reclaimed bricks before laying them, rejecting anything that sounds hollow or shows signs of previous spalling.
New facing bricks. Manufactured to a consistent standard and available in a wide range of finishes designed to replicate older brick tones. Modern engineering-grade stocks are very frost-resistant. The drawback is that a perfect colour match is rare, and new bricks can look noticeably fresh against weathered original courses for several years until they settle.
Class A engineering bricks. Dense, low-absorption, and highly frost-resistant. These are the right choice for the top two or three exposed courses of a stack where the freeze-thaw problem is worst. They are not usually appropriate for the whole stack as they are harder than most original brickwork and can transfer stress back into softer courses below.

Mortar: The Detail That Most Affects Durability

Mortar is where chimney rebuilds most often go wrong, and it is the detail homeowners are least likely to ask about. The key principle is that mortar should always be softer than the brick it bonds. If the mortar is stronger than the brick, stress from thermal movement and frost is absorbed by the brick face rather than the joint - the result is spalling and cracking of the brickwork itself.

Older properties - broadly, anything built before the 1950s - were originally built with lime-based mortars. These are weaker and more flexible than modern sand-cement mixes. When a cement-heavy mortar is used in repairs, the mismatch causes accelerated brick failure. The right approach for older chimneys is a lime or lime-rich mortar mix: typically NHL (natural hydraulic lime) combined with sharp sand. NHL mortars are more weather-resistant than pure lime but still softer than the brick.

Post-war and modern brickwork is usually compatible with a standard sand-cement mix, though even here a small proportion of lime improves workability and adhesion.

When asking a roofer about mortar, the question to ask is: what ratio are you mixing, and is it matched to my brickwork? Any roofer who cannot answer that question directly should prompt further scrutiny.

Flaunching: The Mortar Cap Around the Pot

Flaunching is the sloped mortar collar that seals and supports the chimney pot. It sheds water away from the top courses and holds the pot in position. Standard flaunching is a sand-cement mix applied in a smooth, sloped shape around the base of the pot. It is functional and long-lasting when applied correctly to a clean, sound surface.

An alternative increasingly used on exposed stacks is a flexible roofing mortar or polymer-modified mix. These are more resistant to cracking under thermal movement. The trade-off is cost - they are more expensive than straight sand-cement. On a well-sheltered stack, standard flaunching applied by someone who knows what they are doing will perform well. On a very exposed top with a large pot in an open position, a flexible mix is worth considering.

Lead Flashing: Code or Alternatives

Lead flashing seals the joint between the chimney stack and the roof slope. It is the part of the chimney assembly most likely to be contributing to damp problems even when the stack itself looks sound. When we rebuild a stack, the existing flashing is inspected and replaced if necessary.

Code 4 lead is the standard for chimney flashings: it is 1.8mm thick and the minimum weight recommended for most domestic chimney applications. Code 5 (2.24mm) is heavier and more durable, particularly on wide stacks or high-exposure situations. Both are traditional lead sheet, formed on-site by hand to follow the profile of the roof and stack.

Aluminium and zinc flashings exist as alternatives. They are cheaper but have a shorter lifespan than lead and are less easily formed around complex profiles. For most chimney applications, lead remains the correct material. Well-dressed code 4 lead is expected to last several decades.

Chimney Pots: Practical Options

If the original pot is undamaged it can be reseated in fresh flaunching. If it is cracked, too heavy, or simply the wrong size for the flue, replacement is the better option. The main types are:

Traditional terracotta pots. Durable, available in a wide range of profiles, and compatible with virtually any style of chimney. Cannon-head and roll-top profiles suit most domestic stacks. They are the default choice for any rebuild.
Concrete pots. Cheaper and heavier. The weight can be a factor on a stack that has already shown signs of movement. They are resistant to frost but look utilitarian and are not suited to older or period properties where appearance matters.
Stainless steel liner extensions with cowl. Used where the original pot is removed and the flue is being fitted with a flexible liner for a wood-burning stove. In this case the liner terminates above the stack and a rain cowl is fitted to the liner itself.

Scaffold: Non-Negotiable for Quality Work

All chimney rebuilds are carried out from properly erected scaffold. There is no safe or practical way to rebuild a chimney stack - relaying courses, dressing flashing, bedding and flaunching a pot - from a ladder. Scaffold is part of the job, and the cost is included in any price we quote.