Loft insulation in Christchurch

What is up there now. Most Christchurch lofts have something in them and very few have enough. It has settled, it is compressed wherever anybody has knelt or stored boxes, it is patchy in the middle and missing at the edges, and there are gaps where cables and pipes were pulled through. Dry and even, it stays and we lay over it. Damp, black underneath or contaminated with droppings, it comes out, gets bagged and leaves with us.

Material, chosen for the space. Mineral wool for most Christchurch lofts, as a soft glass wool roll, or a rockwool batt where something denser suits. Loose fill where the joists run at awkward centres or a trussed roof is too tight to work a roll into, and sheep wool if you would rather. Where headroom runs out it becomes PIR rigid board, cut tight and taped at the joints, with a multi-foil quilt for the shallowest corners.

Two layers, the second one crossways. A single layer laid flush between the joists gets a ceiling perhaps a third of the way and leaves every timber conducting heat straight through it. So the first layer goes between the joists and the second is cross laid over the joists, running the opposite way to the first. Around 270mm all in, which is roughly what the Part L U value means once it is wool rather than a number on a page, and one of the cheapest reductions in heat loss these houses have left to make.

Ventilation, and the moisture that follows it. Insulation in a Christchurch loft is taken out to the wall plate and stopped there. The eaves stay open vent trays hold the air gap open above the quilt, so cross ventilation is not interrupted anywhere along the run, and where the eaves cannot be opened up a ridge vent is sometimes the answer. Block them and the vapour that used to leave the roof space condenses under cold felt instead. Insulating moves the dew point upward, interstitial condensation forms inside the layer, and you get wet insulation and black mould spreading on the rafters. BS 5250, the moisture standard for buildings is the reference, and A breathable membrane moves the detail along, but the principle holds.

Services, hatch and rafter level. Recessed lights need a cover rated for the job, not wool laid straight on, cables are clipped above the new depth instead of buried, and any cold water tank and its pipework want lagging once the space around them is cold. The hatch is insulated underneath the loft side and sealed where it lands against draughts. Where there is no loft floor at all, a room in roof has to be done at rafter level, warm roof fashion, with the sloping ceiling and any dormer cheek carried through as one layer.

Floor area has little to do with the price of a Christchurch loft. The open middle goes quickly; getting in and working the edges takes the time, and all of it is work at height.

The hatch. A post-war Christchurch semi with a landing hatch you can stand a stepladder under is easy. A town house with its hatch over the stairwell needs a platform first, and a top floor flat with a small communal hatch means carrying everything up a shared stair.

What is up there. Old quilt bagged and carried down, boxes shifted and returned, and boarding lifted all come before anything new. Joists at 400 centres with nothing in the way go fast. A trussed roof braced every which way, or a terrace loft divided into crawl spaces, goes slowly.

Round the edges. The quilt is kept back from the wall plate so air still moves through the eaves, which counts in damp sea air. The hours go on packing full depth into the corners and round the hatch, boxing over downlighters, and lagging the tank and its pipes, all to the standard in Approved Document L.

Keeping storage. Raised legs and boards over the new layers, if you still want to store things up there, are priced separately.

Ask a rival quote how deep and in how many layers, whether the old quilt is removed, and whether the eaves stay ventilated.

The sea is close enough here to matter, and what it goes for is not the tiles but the metal. Salt settles on a roof and keeps it damp between showers, which corrodes nail heads, clips and fixings from the outside in.

A covering can look perfectly sound from the pavement while what holds it down has quietly gone. The loft is the one place you can see that, because from inside you are looking at the underside of the whole roof at once.

So before the depth goes down we look up. Rust marks running down the underlay, daylight at a verge, a batten that has gone soft, damp staining that follows a line rather than a patch: all of it is easier to read now than after 270mm has been laid over the floor. It matters more than it sounds, because insulating properly makes the roof space colder, and a small defect that used to dry out in a cold loft will not dry out in a colder one. Where we find something, you get a photograph of it and a straight answer about whether it needs doing first, at the same time, or not at all.

We cover Christchurch, Purewell, Somerford, Mudeford, Burton and Highcliffe, and the BH23 addresses around them, 2.7 miles from our Boscombe base, with BCP Council covering planning and building control. You would deal with Bournemouth Roofing & Building Ltd, a company registered in England and Wales, number 15471719. Before you book a visit in Christchurch, you can read our customers' Google reviews, word for word, on our reviews page.

Thomas Hannen, the owner, measures up in your loft and prices the job himself. On Checkatrade there is a 10 out of 10 from a verified customer. There is no charge for the survey visit, or for the written quote with its itemised lines.

Most repairs in Christchurch need no application at all. What decides whether a change to the outside of your house does is who the council is, whether a conservation area or a listing applies, and whether the place sits in a protected landscape.