What Happens During a Complete Re-Roof?

A complete re-roof is not complicated to live through, but there are moments where you will be asked something, and being ready for them makes the difference between a smooth job and a stressful one.

This is the customer's-eye view: what happens, what you will be asked, and what a contractor doing the job properly will tell you without being prompted.

Before the Start Date

What should already be settled

• The covering, named by manufacturer and range — not just “tiles”
• Whether ridge and verge are dry-fixed or bedded
• The rate for defective timber, in writing
• Whether fascias, soffits and guttering are included
• Who is notifying building control, and whether the fee is in the price
• The guarantee: what it covers, for how long, who honours it
• How you will be contacted if a decision is needed mid-job

If any of those is still vague when the scaffold goes up, it will be settled under time pressure later, which is the worst moment to settle anything.

What you should do

• Clear the loft, or bag what is in it — the dust is considerable
• Take down anything on upstairs walls that vibration could dislodge
• Move garden furniture, pots and anything fragile away from the elevations
• Agree where the skip and the materials will go
• Tell the neighbours, with a rough end date
• Move cars off the drive if the materials drop needs it

Day One: Scaffolding

Usually a day or two before the roofers arrive. Quick on an ordinary house, longer on an awkward one. If it has to stand on the public footway a licence is needed, and that is often the longest lead item on the whole job.

You will notice: reduced light upstairs, people able to see in, and the scaffold staying up for the whole job plus a day or two either side.

The Strip

The loudest phase and the shortest. The covering, battens and underlay come off — in sections, never the whole roof at once — and go into a skip or down a chute.

You will notice: real noise, dust coming into the loft, and the roof looking alarming for a day. That is normal. The building stays weathertight because only a manageable area is ever open, and anything open is sheeted at the end of the day and whenever weather requires.

The Structure Inspection

Brief on a sound roof, longer where something needs attention. Rafters, purlins and wall plates are looked at, with particular attention to the rafter ends where they sit on the wall plate — the commonest place for rot, because that is where a failing gutter has been putting water for years.

Ask for photographs. This is the one moment the structure of your house is visible, and once the underlay goes on it is invisible again for decades. The pictures cost nothing and they are your evidence of what was there.

Rebuilding

The longest phase, and the quiet one. Underlay, battens, covering, lead, ridge, verges, ventilation.

Worth looking at while you still can:

• The underlay, before the battens go over it — is it lapped properly and dressed into the gutter at the eaves, rather than stopping short behind it?
• The battens, before the covering — new, treated, evenly spaced? They should carry printed markings showing they are graded to the British Standard, which you can read off the timber.
• The lead, at chimneys and abutments — formed and dressed into the brickwork, not bedded in mastic?
• The ventilation at the eaves — a clear path, not blocked by insulation pushed hard into the corner?

None of this requires expertise. It requires looking before it disappears. Roofing is layered work and every layer hides the one below it.

Insulation and Ventilation

Part of the job where the threshold is crossed, not an extra. On a cold loft the insulation goes at ceiling level; where the roof space is a habitable room it has to go at rafter level instead, which is a bigger job and should have been priced as one.

Ventilation matters just as much and gets less attention. Add insulation and a membrane without providing airflow and you get condensation on the underside of the roof. Insulation stuffed hard into the eaves blocks the path the roof needs — a common fault, and easily avoided with a proper eaves detail.

Finishing and Handover

• Gutters cleared and tested with water
• Site cleared, and a magnetic sweep for nails — ask, if it is not offered
• Scaffold struck a day or two after completion
• A walk round with the contractor before final payment

The paperwork you should end up with

• A building regulations compliance certificate
• A written guarantee, stating what is covered, for how long, and by whom
• Any manufacturer warranty for the covering
• Photographs of the structure and any concealed work

Keep all of it with the deeds. A buyer's solicitor will ask for the certificate and the guarantee, and finding them a decade later is otherwise a problem you have made for yourself.

What Should Not Happen

• The whole roof opened at once
• Work continuing in high wind or heavy rain
• Defective timber replaced without being shown to you first, or charged at a rate never discussed
• A request for a large additional payment mid-job
• The old covering left on site after completion
• No certificate offered, or vagueness about who is providing one

If any of those happens, raise it that day. Everything on a roof gets covered by something else within about a day, and the conversation is far easier while the thing you are asking about is still in view.

The Regulations, in Brief

Two systems, and they are separate. Planning: a like-for-like re-roof does not materially affect the external appearance of a building, so under section 55 of the Town and Country Planning Act 1990 it is not development at all and needs no permission. A visible change of covering can be a different matter, particularly inside a conservation area.

Building regulations: where more than 50% of the roof's surface area is renewed, or the work forms part of a major renovation, regulation 23 of the Building Regulations 2010 requires the roof to be brought up to current thermal standards so far as that is technically, functionally and economically feasible. A patch repair does not trigger it, and neither does a roof over unheated space such as a detached garage. The work is signed off through building control or by a roofer registered under a competent person scheme, and you should receive a certificate.

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