Pipe and tank lagging
Pipe and tank lagging wraps the cold water tank, the feed and expansion tank and the pipes in a loft with insulation so they do not freeze. It matters most after loft insulation, because a well-insulated loft runs at close to the outside temperature on a winter night. It is included in every loft insulation and top-up job we do, and available on its own.
What is pipe and tank lagging?
We fit a jacket to the top and sides of each tank and foam lagging to every exposed pipe, taped at the joints and bends. The ceiling under the tank is left uninsulated so warmth from below can reach it. Overflow pipes and any condensate pipes in the loft are included.
Is it right for your loft?
- Someone else insulated the loft and left the pipes bare
- Pipes in the loft with no lagging or split lagging
- A tank with no lid or jacket
- A pipe has frozen before
How we do it
- We trace every pipe and tank in the loft.
- Old, split lagging is removed.
- Tank jackets and lids are fitted.
- Pipes are lagged and taped at joints and bends.
What is included
- Tank jacket and close-fitting lid
- Foam pipe lagging, taped
- Ceiling under the tank left clear
Worth knowing
Lagging slows freezing but cannot stop it in a long hard frost if pipes are in an exposed eaves. We may suggest rerouting a pipe.
How much does pipe and tank lagging cost?
Installing insulation in a home is zero-rated for VAT until 31 March 2027 and 5% after that, under HMRC's rules for energy-saving materials (notice 708/6).
Do the rules differ across the UK?
Yes, a little. Building regulations and funding schemes are set separately in each nation. Here is the short version; each area page has the detail.
| Nation | Building rules | Funding to check |
|---|---|---|
| England | Approved Document L; insulation alone is not usually notified | ECO4 to 31 Dec 2026; Warm Homes Plan and Warm Homes: Local Grant |
| Wales | Welsh Approved Document L; conversions need building control | Warm Homes Nest; ECO4 to 31 Dec 2026 |
| Scotland | No building warrant normally needed; standards still apply | Home Energy Scotland grant and loan; Warmer Homes Scotland |
| Northern Ireland | NI Building Regulations (Technical Booklet F1); check with council building control | Affordable Warmth Scheme; NISEP |
Questions about pipe and tank lagging
Should I insulate under the water tank in the loft?
No. Leave the ceiling directly under the tank uninsulated so a little warmth from the house reaches it. Insulate the top and sides instead.
Is pipe lagging included with loft insulation?
Yes. A tank jacket and pipe lagging in the loft are included in every loft insulation and top-up price. If you only need lagging, it is priced on its own.
Do I need a lid on my cold water tank?
Yes. A close-fitting lid keeps debris and insects out and is part of the water regulations for cold water storage.
Where we provide pipe and tank lagging
England
- Bedfordshire
- Berkshire
- Bristol
- Buckinghamshire
- Cambridgeshire
- Cheshire
- Cornwall
- County Durham
- Cumbria
- Derbyshire
- Devon
- Dorset
- East Riding of Yorkshire
- East Sussex
- Essex
- Gloucestershire
- Greater London
- Greater Manchester
- Hampshire
- Herefordshire
- Hertfordshire
- Isle of Wight
- Kent
- Lancashire
- Leicestershire
- Lincolnshire
- Merseyside
- Norfolk
- North Yorkshire
- Northamptonshire
- Northumberland
- Nottinghamshire
- Oxfordshire
- Rutland
- Shropshire
- Somerset
- South Yorkshire
- Staffordshire
- Suffolk
- Surrey
- Tyne and Wear
- Warwickshire
- West Midlands
- West Sussex
- West Yorkshire
- Wiltshire
- Worcestershire
Scotland
Often booked with it
Sources, checked October 2026: Energy Saving Trust: roof and loft insulation; Which?: loft insulation costs and savings; LABC: building regulation requirements for loft insulation; GOV.UK: extending the ECO4 end date, government response.
