SuperFOIL SF19+ in Yorkshire: Roofs, Outbuildings and When to Avoid It on Stone

Yorkshire has some of the most characterful buildings in England: stone cottages, mill-town terraces, farmhouses and barns, many of them standing on exposed ground. They are also some of the trickiest buildings to insulate well. A product that is right for a 1990s timber-framed garage can do harm on a 19th-century solid stone wall. This guide is a straight look at where SuperFOIL SF19+ multifoil insulation belongs on Yorkshire jobs, and, just as important, where it does not.

For the product itself, see our complete SuperFOIL SF19+ guide.

Quick answer

• SF19+ has a foil face that works as a vapour control layer. That is useful in a modern timber roof or outbuilding, but it is a risk on traditional solid stone walls that need to breathe.
• Good fits: roof spaces with a sound, dry structure, garages, workshops, barns used for storage or hobbies, and timber floors.
• Poor fits: damp or solid stone walls, and anything where moisture has nowhere to go.
• Exposed upland sites need extra attention to weatherproofing, ventilation and condensation.
• We have a £400 ex VAT minimum, with free delivery in England. British Gypsum (including Gypframe), Celotex and Knauf can also go to mainland Wales and mainland Scotland (£400 ex VAT minimum plus £40 + VAT delivery). Access panels can also go to mainland Wales and mainland Scotland, with their own charges (£15 + VAT under £300 ex VAT, free from £300). Other ranges, including suspended ceiling tiles and grid, are delivered in England only. We do not deliver to Northern Ireland or the Scottish islands., which includes all of Yorkshire.

Start with the wall, not the product

Historic England's guidance on traditional buildings is consistent: solid stone and brick walls manage moisture by letting it move through and evaporate. Sealing them behind impermeable layers can trap moisture and lead to condensation, mould and decay. Its advice is to use vapour-permeable, moisture-managing materials and to resolve damp problems before you insulate. Where a vapour control layer is used at all, it is hard to keep sealed at joints, penetrations and edges.

SF19+ is built the other way round. Its aluminium foil face is a vapour control layer, and its Kiwa Agrément covers an internal wall system with conditions: the walls need to be free from damp and mould, and the Agrément expects a condensation risk analysis for the project. So for a damp stone cottage, SF19+ is not the product to reach for. If your Yorkshire house is a solid-wall stone building, read our solid wall guide, get the wall assessed, and consider a specialist or a breathable system. If the building is listed, you will need consent before altering it.

Weather and exposure

The Met Office describes the Pennines as markedly wetter than areas to the east, with rainfall over 1,500mm a year in the higher Pennine areas. The North York Moors also receive over 1,000mm in places. You do not need to live on the tops to feel the effect: wind-driven rain finds weak points in roofs, flashings and window surrounds. Before any insulation goes in, SuperFOIL's own guide asks you to check roofs, gutters, downpipes and rainwater systems, and to confirm windows are intact with no water leakage. On an exposed stone building, that check is the job.

Where SF19+ does suit Yorkshire buildings

Garages, workshops and farm outbuildings

A dry, modern garage, workshop or timber-clad outbuilding is a good fit for a flexible roll. You can fit it under the roof rafters and between wall studs, keep the air gaps on both sides, and tape every joint. Our shed and garage insulation guide explains the wider approach. Unheated buildings that are used occasionally are prone to condensation, so ventilation matters.

Roofs over barns and conversions

Converted barns and agricultural buildings often have large, simple roofs. SuperFOIL's under-rafter method works on conventional pitched roofs: overlap rolls by at least 50mm, staple at no more than 300mm, counter-batten at no more than 600mm centres, tape all joins, and keep an air space either side. Existing roof ventilation should be maintained. Remember the roll cannot be walked on, so install it from below. Check for asbestos in older agricultural roofing before you touch it.

Timber floors in terraces and cottages

Suspended timber ground floors are found in many older homes, and they are an area where SuperFOIL recommends SF19+. Fitted between the joists with the correct gap and taped at edges, it can cut heat loss through the floor. Fix any damp first, and keep underfloor ventilation clear. Our suspended timber floor guide covers the PIR alternative.

Room-in-the-roof in terraces

Historic England recommends vapour-permeable insulation for traditional roofs, and a foil-faced roll is the opposite. If the roof is a modern replacement or a well-ventilated modern build-up, SF19+ can be considered. If the roof is old, with original timbers and slates, take advice first.

Planning and building regulations

Loft conversions may fall under permitted development, but the Planning Portal says that does not apply on designated land such as National Parks. Yorkshire includes the Yorkshire Dales and the North York Moors National Parks, and conservation areas are common in historic towns and villages, so check before you commit to a loft room. Building regulations approval is needed for any loft conversion. Approved Document L requires the roof of a converted loft to meet the limits in Table 4.3 (the improved roof U-value there is 0.16 W/m²K), with allowance where headroom would be limited.

See also our building regulations for insulation guide.

When wool or PIR is the better choice

• Stone or old brick walls that must breathe. Use mineral wool or another vapour-open system, designed by someone who understands traditional buildings.
• Standard cold lofts. Mineral wool at depth, as in our 270mm loft guide.
• Newer cavity-wall homes. Insulated plasterboard or a cavity fill is normally easier than building out an air-gap system.
• Anywhere depth is tight. PIR delivers more per millimetre than a roll that needs air gaps.

Our wool vs PIR vs foil comparison goes through each, and you can work out quantities with our insulation calculator.

Frequently asked questions

Can I use SF19+ on a Yorkshire stone cottage wall?

We would not recommend it without specialist advice. Traditional solid stone walls need to let moisture out, and SF19+ has a foil vapour control layer. Get the wall assessed first.

Is SF19+ okay for a barn conversion roof?

It can be used on a sound, ventilated pitched roof using the under-rafter method, but the whole build-up should be designed to meet Building Regulations and checked for condensation risk.

Does it work in unheated outbuildings?

Yes, on the same principles as a house: build in the air gaps, tape the joints and keep the structure dry. Condensation is the main risk.

Do you deliver to Yorkshire?

We have a £400 ex VAT minimum, with free delivery in England. British Gypsum (including Gypframe), Celotex and Knauf can also go to mainland Wales and mainland Scotland (£400 ex VAT minimum plus £40 + VAT delivery). Access panels can also go to mainland Wales and mainland Scotland, with their own charges (£15 + VAT under £300 ex VAT, free from £300). Other ranges, including suspended ceiling tiles and grid, are delivered in England only. We do not deliver to Northern Ireland or the Scottish islands., which includes Yorkshire. See our delivery information.

Order SuperFOIL SF19+

Order SF19+ in 1.2m x 10m or 1.5m x 10m rolls, or browse the whole SuperFOIL multifoil collection. Current trade prices are shown on each product page. We have a £400 ex VAT minimum, with free delivery in England. British Gypsum (including Gypframe), Celotex and Knauf can also go to mainland Wales and mainland Scotland (£400 ex VAT minimum plus £40 + VAT delivery). Access panels can also go to mainland Wales and mainland Scotland, with their own charges (£15 + VAT under £300 ex VAT, free from £300). Other ranges, including suspended ceiling tiles and grid, are delivered in England only. We do not deliver to Northern Ireland or the Scottish islands. (see delivery information). Call us on 03330 908479 (Mon–Thu 8am–5pm, Fri 8am–12pm), email sales@insulationwarehousedirect.co.uk, or order online.

Sources: Historic England: risks of energy efficiency interventions in buildings of traditional construction; Historic England: insulating walls in historic buildings; Met Office: North East England and Yorkshire climate; Planning Portal: loft conversions; Approved Document L (Conservation of fuel and power); SuperFOIL SF19+ product page; Kiwa BDA Agrément BAW-24-342-S-A-UK; SuperFOIL under rafter installation guide; SuperFOIL floor installation guide.