Costs & quotations

How much contingency should I allow for a reroof?

Short answer: The right contingency depends on how much structure is concealed and the quality of the survey. Older complex roofs normally justify more allowance than open, recently inspected construction.

What this means in practice

Compare quotations line by line, including VAT, scaffold, waste, exact products, insulation, ventilation, leadwork, timber allowances, Building Control, payment terms and guarantees. A low total created by missing essential work is not a saving—it is an unpriced variation waiting to happen.

What to check next

  • List credible hidden risks
  • Use capped allowances where possible
  • Keep contingency outside the contractor's base price

When should you ask a roofer to inspect it?

Get a measured, written quotation before committing to substantial work. Ask questions wherever wording is vague, and insist that hidden defects are photographed and priced for approval before extra work proceeds, except where immediate safety action is unavoidable.

Safety first: do not climb onto a roof without suitable access, training and protection. Keep clear of loose coverings, unstable ceilings and water near electrical fittings.

Technical content reviewJ & L Welch Roofing & Paving Services Ltd · Over 20 years of combined roofing experienceReviewed 28 August 2026 · How our answers are produced

Would you like a property-specific answer?

Request an inspection and written quotation from J&L Welch.

No deposit is required. Payment is due on completion within seven days, with the agreed scope and price confirmed in writing.

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