Loft insulation in New Milton

Seal it before you fill it. An uninsulated hatch with nothing round the frame is a chimney out of your landing, and it quietly undoes a good deal of whatever gets laid above it. So the hatch takes insulation on its back and a compression seal on the frame, and the loft ladder is tried afterwards to make sure it still drops clear. The holes where pipes and cables come up through the plaster get closed. Recessed lights are the other way out, and every one of them takes a fire rated hood instead of wool tucked round the fitting. None of that is expensive, and it decides how much of the depth you actually get to keep.

What comes out, and what stays. Very little up here is bare and very little is anywhere near depth. The old layer settles, gets compressed under boards and feet, goes patchy across the middle and is missing altogether at the edges. Dry and sound, it is straightened out and kept under the new work. Wet, or contaminated with droppings, it is bagged at the hatch and taken away, priced on a line of its own. A ceiling with a thermal bridge at every joist and a draught coming off the hatch will not hold its heat whatever the packet on the roll claims.

Then the depth, in two crossed runs. A single layer sitting level with the joists gets a ceiling perhaps a third of the way to where it ought to be, with every timber conducting heat straight up through it. So one run goes in between the joists and a second is turned square and laid across them. Around 270mm all in puts the ceiling at the u value Approved Document L expects, and for most houses on this side of town it is the largest single cut in heat loss still going. Glass wool rolls or the denser rockwool batt do most of the work. A loft with joists at odd centres, or a trussed roof too tight to open a roll out in, is better served by loose fill, poured or blown. Rigid PIR board where headroom is the constraint, multi-foil quilt behind that, and sheep wool if you would rather have it.

The perimeter is where the hours go. Insulation is taken out over the wall plate and stopped dead, and a vent tray goes into each rafter bay to hold an open channel above it. That channel is what lets the roof breathe over the top of the new depth. Fill the eaves instead and the moisture leaving your house has only cold felt to land on: interstitial condensation forms inside the layer where nobody looks, and by the end of the winter there is wet wool and black mould up the rafters. The ventilation standard behind that is Approved Document F, and a breathable membrane alters the detail at the edge rather than the principle.

Tanks, cables, and roofs that are already rooms. Cables are dressed over the new depth instead of under it, since cable buried in insulation runs warm. The cold water tank and the pipework with it are standing in cold air now, so both get lagged and the patch beneath the tank is left thin on purpose. If the loft carries storage, the boarding goes back up on loft legs above full depth rather than flat on the joists, and only the part you use is boarded. Where the roof has already been turned into a room, the whole job moves up to the rafters: board between them, board under them, a clear gap kept behind, taped joints, and the sloping ceilings and dormer cheeks treated as one continuous warm roof.

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 post-war semi with a small landing hatch, a bungalow with a wide loft you can move about in, and a top floor flat reached through a communal hatch are three different jobs, and the first of them is work at height on a ladder. 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.

A quarter of the homes here are flats and maisonettes, which makes one question more useful in New Milton than almost anywhere else on this list. Is the roof void above your ceiling part of what you lease, or is it retained by the freeholder? A good many leases stop at the plaster. Where yours does, the loft is not yours to insulate, and a contractor who goes up on your word alone has put you in the wrong rather than saved you money.

The way through it is dull but quick. Look at the lease plan and the demise wording, then put the question to the managing agent in writing. We are happy to survey, quote and send the specification straight to the agent, and where a block wants to do the whole roof at once we will price it that way, but we will not open a communal hatch on a verbal yes. It is worth starting early, because a block decision moves at the speed of a managing agent rather than at the speed of the weather, and a loft booked in the spring is a loft finished before the winter it was meant for.

We cover New Milton, Barton on Sea, Ashley, Bashley, Tiptoe and Hordle, and the BH25 addresses around them, with New Forest District Council as the planning and building control authority. 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.