Loft insulation in Ashley Heath

Topping up what is there. The usual find is one layer of mineral wool between the joists, finished flush with the top of them. That was the standard once, and it leaves every joist acting as a cold bridge through the middle of the insulation. Sound material stays, gets straightened and pushed back into the gaps where it has settled, and a second layer of unbacked roll goes over the top, running across the joists rather than along them. Two layers, the second one crossing the first, is what gets you to about 270mm finished. When it is in you cannot see the timber any more.

Clearing first. Some of it has to come out. Material that is wet, patchy where somebody has walked through it or contaminated with droppings gets bagged and carried out rather than covered over, and so does the loose fill you still meet in older houses, which drifts into the eaves and blocks them.

Working in a trussed roof. Much of the housing here went up in the 1970s and early 1980s on trussed rafters, which is bracing to work around rather than a clear space you can move about in. Nothing is stood on the ceiling. We work off boards laid across the joists and do the far corners first, because the corner left until last is the one that ends up missing its depth.

The eaves, and why we stop short. Insulation runs out over the wall plate and then stops, with a clear air gap above it. Eaves vent trays hold that gap open so the roll cannot be pushed into it, and cross ventilation still works from one side of the loft to the other. Fill the eaves and you have a warm bedroom under a wet roof, with condensation running off the underside of the felt and black mould along the timbers by February. A breathable membrane is more forgiving than old bitumen felt, but the edge detail is the same either way.

Services, storage and sloping ceilings. Recessed lights get fire rated covers, and cable is lifted and clipped above the new layer instead of being buried, because wiring in insulation runs hot. A cold water tank and its pipework end up on the cold side, so pipes are lagged, the tank gets a jacket and a lid, and nothing is laid underneath it. The hatch gets an insulated board and a draught seal. If you use the loft, we build a raised floor on loft legs so the boarding sits above full depth, and set the loft ladder to suit. Where a chalet bungalow has a room in the roof it becomes rafter level work instead: rigid board between the rafters with the air gap open above, PIR under, taped so the vapour control is continuous.

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 bungalow with the hatch on a hallway ceiling, a chalet bungalow where the only access is a small opening on an upper landing, and a detached house with a boarded loft over the garage are three different mornings before a roll is opened. 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.

Just over half the homes in Ashley Heath are bungalows, and that changes the sums. Every room sits directly under the roof, so the ceiling you are insulating is roughly twice the area it would be in a two storey house of the same floor space. Heat loss upward is the largest single thing you can do anything about here, and the loft is the cheapest place in the building to do it.

The catch is the shape of the roof. A bungalow comes down to head height at the edge, so the last metre over the wall plate is the awkward one, and it sits directly above the outside wall of a room you use every day. That corner is where a rushed job stops, and you feel it as a cold strip along the back bedroom wall. We get out there on boards, fit trays so the air gap survives, and carry the depth into the corner rather than tapering it away. A hipped bungalow roof has four of those edges instead of two, which is why they are a separate line on the quote.

We cover Ashley Heath, St Leonards, St Ives, Ringwood and the BH24 addresses around them, with Dorset Council for 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.