Loft insulation in Downton

The ceiling below carries nothing at all, so nothing gets stood on. Two boards get laid over the joists and moved along as we go, working outwards from the hatch. Where the void will not let you sit upright, the whole thing happens on hands and knees, and that shows up as hours long before any material is opened. Anything you have stored up there comes down first. Getting in and out is priced at the survey. Indoors or not, a loft is work at height.

In a house of this age the joists are hand cut and the spacing wanders along the run, so the first layer is cut to each bay rather than rolled out and hoped over. Batts often beat a roll for that. Where the void is genuinely shallow, rigid PIR board cut tight and taped gets more out of the same depth than any quilt does, and multi-foil earns its place in the last few inches.

Where there is room, the answer is the ordinary one. Whatever is between the joists is straightened and kept, and a fresh run of mineral wool goes over it, turned at right angles so it lies across the joists and hides the timber instead of leaving it standing proud. Around 270mm together is the u value Approved Document L expects of a renovated ceiling. Glass wool, rockwool or sheep wool, whichever suits the roof and suits you.

The eaves stay open whatever the depth. The layer runs to the wall plate and stops, vent trays hold the gap above it clear in every rafter bay, and ventilation crosses from soffit to soffit. Plenty of roofs in the old village were never felted and ventilate themselves without any help. Recover one under a breathable membrane, or box the soffits in under old bitumen felt, and that easy path can close up without anybody noticing. What you see afterwards is water on the felt first thing and black mould working its way along the rafters. Interstitial condensation does its work inside the layer long before any of that shows.

Then the parts nobody counts. Recessed lights take a rated cover each. Wiring is clipped over the new depth instead of buried under it. The cold water tank, its overflow and every pipe near it are out in the cold now, so all of it is lagged. Anything you store goes back onto loft legs standing clear of the wool, the hatch gets a board and a seal, and the loft ladder is tried against the new floor before we leave. Where a roof was converted years ago the whole approach changes. Sloping ceilings and dormer cheeks get lined in rigid board, some of it between the rafters and some fixed under them, an air gap kept clear behind, and every joint of the vapour control layer taped so warm air never reaches a surface cold enough to wet it. That build up is a warm roof and it takes a full day of careful work.

No rate per square metre, because the floor area is the easy part and the awkward edges are where the time goes.

Getting to it. A terrace with the hatch on the landing, a cottage where the void is too shallow to sit up in, and a detached house on the edge of the village are three different jobs. A hatch on a landing you can stand a ladder under is one job. A hatch over a stairwell, a crawl space you can only move through on your knees, or a loft full of boarding that has to come up and go back, is time before any material is laid.

What is up there now, and what it is sitting on. Old material that has to come out, be bagged and taken away is a cost before anything new goes down, and so is a loft full of boxes that has to be emptied and put back. Joists at 400 centres with a flat run across them is a different afternoon from a trussed roof full of bracing.

Ventilation, and the edges nobody reaches. Insulation stops at the wall plate and the eaves have to stay clear, or you trade a warm bedroom for a wet roof. Getting depth right into the corners and around the hatch, boxing over downlighters and lagging anything that now sits in the cold, is most of the labour. Approved Document L sets what the work is expected to reach.

Comparing quotes? Ask what depth is actually being laid and in how many layers, whether the old material is coming out or being covered over, whether the eaves are being kept clear, what happens to anything you store up there, and whether the hatch and the pipework are included. Two quotes for the same job are usually two different jobs.

We cover Downton, Redlynch, Morgan's Vale, Charlton All Saints, Fordingbridge and the SP5 addresses around them, with Wiltshire Council for planning and building control. You are dealing with Bournemouth Roofing & Building, the trading name of Bournemouth Roofing & Building Ltd, registered in England and Wales, company number 15471719, which you can look up in a minute. Thomas Hannen's business, and he is the one who comes out to price the job, not a salesman. A verified customer's 10 out of 10 on Checkatrade. The visit and the written quote are both free.