Loft insulation in Bere Regis

Reading what is already there. Depth first, condition second. Wool that has settled or been compressed to half its thickness insulates to half its value, and a layer that looks even from the hatch is usually patchy, or missing altogether, once you are out at the far corner. Anything wet or contaminated gets bagged and taken away, and loose fill that has drifted into the eaves comes out of them whatever else happens.

Depth, in two layers. Sound material is straightened and left between the joists. The new roll goes over the top of it at right angles, so the joists are covered rather than left standing proud as a line of cold bridges through the ceiling. Two layers laid across each other get you to roughly 270mm, and a finished loft should look like a flat field with no timber showing. Glass wool or rockwool roll suits an open floor, batts are easier where a run is broken up by bracing or a chimney breast, and sheep wool is there if you want it. The gain is in the U value of the ceiling, and most of the heat loss you can still do something about is going straight up through it.

Older roofs, and what you can stand on. Plenty of the houses here have a traditional cut roof with purlins, which is a good deal easier to move about in than a modern trussed loft, but the ceiling below is often lath and plaster and will not take a foot. Nothing is laid off the ceiling. We work from boards and keep to the joists. Where there is already a room in the roof, a dormer or a sloping ceiling, the work moves up to the rafters instead: rigid board such as Celotex cut tight between them with the air gap left open above, a layer of PIR beneath, taped through so the vapour control is continuous. That is a warm roof build up, and it is priced as its own job.

Moisture is the part to get right. Insulating a loft makes it colder, which pushes the dew point onto the underside of the roof. If house air can get up there, you see droplets on the felt and black mould along the timbers within a winter. So the hatch is sealed, gaps around pipes and cables are closed, the eaves are kept clear with trays, and cross ventilation is checked from one side to the other. An older roof with no underlay ventilates itself well; a sealed modern one relies on the eaves you are about to lay up to. BS 5250 on managing moisture in buildings is the code of practice behind all of that.

The rest of it. Recessed lights are boxed with fire rated covers, cable is lifted clear rather than buried, and the tank and its pipework are lagged and jacketed once they sit on the cold side. Where the loft is used for storage, boarding goes onto loft legs above full depth instead of flat on the joists, with a platform at the top of the loft ladder.

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 village cottage with a small trap in a bedroom ceiling, a bungalow with a proper landing hatch and a ladder, and a barn conversion where the roof space is reached through a cupboard are three quite different half days before any material is laid. 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.

The village drains into the Poole Harbour catchment, which is protected, and that has one practical consequence worth knowing before you plan anything. Nutrient rules bite on schemes that add overnight accommodation, so turning your loft into a bedroom can pull you into them. Insulating the loft you already have does not: nobody is sleeping up there, no extra foul drainage is created, and there is nothing to apply for.

It matters because the two get talked about as if they were one job. If the loft stays a loft, the material goes over the ceiling, the eaves stay open and the roof space stays cold. If it becomes a room, the insulation moves up to the rafters, the space becomes warm, and the ventilation, the vapour control and the structure all change with it. That is a different design and a different set of consents. We will price either, and if you are undecided we will say which parts of the work would be wasted by converting in a couple of years.

We cover Bere Regis, Winterborne Kingston, Wool, Bovington and the BH20 addresses around them, with Dorset 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.