Velux and Roof Window Repairs in Manchester

Where a roof window actually leaks

Nine times out of ten the water is not coming through the glass. It gets past the flashing where the window meets the covering, and we nearly always find it in this order. The collar under the top flashing perishes, or was never dressed down onto the felt, so anything blowing past the head has nowhere to go but inwards. Then the side pieces lift where the tiles beside them were cut short. Then the apron at the bottom is pushed up by a tile that has crept down the pitch. A window fitted with the wrong kit for the profile can look perfect from the ground and take water in from the day it went in.

Telling a leak from condensation

Two tests, and both are free. First, when does it show? Water during or just after driving rain, especially wind from one direction, is a leak. Water on a cold still morning, worst in winter over a bathroom or a kitchen, and gone by lunchtime, is condensation. Second, where does it show? A leak comes in at one corner and runs down the plaster reveal, staining the timber lining from the top down. Condensation forms across the whole pane and drips off the bottom of the frame in an even line.

What happens if it is left

A roof window sits in an opening framed in timber, and that timber is what gets ruined, out of sight. Water past the head flashing runs down the trimmer and along the top of the plasterboard lining, so the first thing you notice is the corner of the reveal going soft and the paint lifting. Left longer the lining board delaminates and the timber round the opening starts to rot, and what we came to do as a flashing job turns into carpentry and plastering as well. Condensation does the same more slowly and adds mould round the seal.

Flashing kits, and why the profile matters

A roof window is weathered by a kit, not by sealant. The kit is a set of pieces sized for the depth of the covering: a flat one for slate and plain tile, a deep one for profiled interlocking tile, plus an underfelt collar that takes anything past the top piece back out onto the felt, and an insulation collar round the frame. We renew the whole kit rather than swap the piece that failed, because a mixed kit leaves a step for water to stand in, and we reset the courses round it so the side pieces are covered rather than proud. What we will not do is run a bead of mastic round the outside of a window and call it repaired.

Misted glass, seized handles and worn seals

Not everything wrong with a roof window is a roof problem. Misting between the panes means the sealed unit has failed and cleaning will not touch it, but on many windows we can put a new glazing unit into the sash you already have. A handle that will not turn, a sash that has dropped, a blind off its runners and a perished draught seal are all parts, and parts are usually still available for a window with its data plate on the top edge of the sash. Find that plate before you ring us: it gives the make, the size code and the year, and it is the difference between ordering the right part and guessing. Dave prices the parts and the labour in a free written quote either way.

The roofs these sit in round here

Most of what we see is loft conversions on 1930s semis, where two or three windows have gone into a clay or concrete tile pitch and the deep profile kit is the one left out. On the Victorian terraces through Chorlton, Didsbury and Monton it is Welsh slate, which wants a flat kit and proper side soakers rather than a tile flashing bent to fit. Rear extensions and dormer cheeks are the third case: a window in a shallow pitch or a flat roof needs a different kit and a kerb to sit on. If the flat roof round it is at the end of its life, or the pitch is nail sick, we would rather say so than fit a good kit into a covering that is coming off in two years.

Repair or replace, and what affects the price

Reflashing is right when the unit still opens, closes and seals and the glass is clear. Replacement is right when the sash is twisted, the frame has gone at the bottom rail, or parts for that model are no longer made. A like for like unit into the existing opening is a much smaller job than making a new hole, because nothing structural is touched. What moves the figure is how we reach the window, since one in a rear pitch over a conservatory wants a tower rather than a ladder; then the covering, because cutting round a deep interlocking tile takes longer than round slate; then how many windows we do in one visit. Dave tells you which of those apply and puts it in a free written quote.

Frequently Asked Questions

The glass is misted on the inside. Can that be fixed?

Misting between the panes means the sealed unit has failed, and cleaning will not touch it. On many windows that is a new glazing unit into the sash you already have. Find the data plate on the top of the sash and we can tell you which applies to yours.

Water runs down the wall under the window every winter but the roof outside is sound. What is that?

Almost certainly condensation rather than a leak, especially if it is over a bathroom and it dries back during the day. That is ventilation, and no roof work will fix it. We will say so on the visit rather than sell you a flashing kit you do not need.

Can you put a roof window in where there is not one already?

That is a different job to repairing one. A new opening means cutting and trimming rafters, which is structural work rather than covering work. Ring Dave and ask him straight: he will tell you whether it is a job he takes on or whether you want a joiner first.

Do you need a scaffold to do a roof window?

Not always. A window low in a rear pitch can often be reached off a tower. Anything high, anything on a gable, or a window over a conservatory where nothing can be leant on wants a proper scaffold. We decide that on the visit and it is in the free written quote.

I have three windows and only one leaks. Should I do them all?

Only if the other two are failing. If they went in together with the same kit it is worth looking at all three while the access is up, because the tower and the labour are the expensive part. If two of them are sound we will say so and do the one.