Roof Waterproofing Preston
Where roofs let water in
Every roof has a handful of weak points where water is most likely to get through. These are the places we check first.
| Weak point | What goes wrong | How we make it watertight |
|---|---|---|
| Tiles and slates | Slipped, cracked or missing, letting rain under | Replaced and secured, matched to the roof |
| Ridges and hips | Mortar cracked or washed out | Re-bedded and pointed |
| Valleys | Worn or blocked where two slopes meet | Cleared, repaired or relined in lead |
| Flashing | Lead lifted, split or badly fixed | Renewed in Code 4 or Code 5 lead |
| Chimneys | Failed pointing, flaunching or flashing | Repointed, new flaunching, new flashing |
| Roof windows and dormers | Failed seals and flashing around the frame | Flashing and junctions renewed |
| Flat roofs | Splits, blisters, failed joints, ponding water | Repaired or re-covered in felt, EPDM or GRP |
| Gutters | Overflowing into the roof edge and walls | Cleared, repaired or replaced |
Waterproofing pitched roofs
On a pitched roof, the slates or tiles shed most of the rain, but they rely on the details around them. Water gets in where the covering is broken, where the ridge mortar has failed, or where the roof meets something else: a chimney, a wall, a roof window or another slope.
Waterproofing a pitched roof means putting each of those details right. That might be replacing broken tiles, re-bedding a ridge, relining a valley or renewing the lead around a chimney. Underneath, the felt or membrane is the roof's second line of defence. If it has broken down across the roof, no amount of surface repair will keep the roof dry for long, and a new roof may be the better answer. See our roof replacement page.
Waterproofing flat roofs
Flat roofs on extensions, dormers and garages are the most common source of leaks, because water sits on them for longer. Splits, blisters, failed joints and edges that have lifted all let water through, and ponding water speeds up wear. Depending on the condition of the roof, we repair the existing covering or replace it with felt, EPDM rubber or GRP fibreglass, laid to proper falls so water drains away. See our flat roofing page. For more detail, see our flat roof waterproofing in Preston page.
Roof windows, dormers and abutments
Anywhere the roof is interrupted is a potential leak. Roof windows rely on their flashing and seals, dormers have their own small roofs and cheeks, and extensions meet the main house at an abutment that needs lead flashing tucked into the wall. These junctions are often where a roof that otherwise looks fine lets water in. See our leadwork roofing page.
Why patching one spot often doesn't work
Water rarely comes in where it shows up. It can enter at a cracked tile or a gap in the flashing, run along the felt or a timber, and appear on a ceiling some distance away. Patching the area above the stain can miss the real cause entirely. That's why we look at the whole roof and, where we can, the loft before recommending a repair. For more on tracing leaks, see our roof leak repairs page.
Sealants and coatings
Sealants and quick coatings can be useful as a temporary measure, but they're rarely a lasting fix on their own. They crack and come away as the roof moves with the weather. Where lead, mortar or a roof covering has failed, renewing it properly lasts far longer. We'll always tell you which approach we're recommending and why.
How we waterproof a roof
- Find every entry point, on the roof and in the loft where we can get in.
- Explain what we found in plain English, with what we recommend fixing now and what can wait.
- Quote before any work goes ahead.
- Carry out the repairs, matching the existing materials.
- Check the work, and the areas around it, before we leave.
Roof waterproofing and damp inside
Damp near the top of a wall or on a ceiling, that gets worse after rain, usually points to the roof, the gutters or the chimney. Not all damp comes from the roof, though: condensation and plumbing leaks can look similar. If we think the cause isn't the roof, we'll tell you, so you don't pay for roofing work you don't need. See also damp prevention roofing.
Homes, landlords and businesses
We waterproof roofs on houses, rental properties and commercial buildings. For larger roofs on offices, shops, warehouses and units, see our commercial roofing page. For everything in this category, see our waterproofing company services.
Frequently asked questions
How do you find where my roof is letting water in?
We check the roof and, where we can, the loft, looking for the point where water gets in rather than where it shows inside.
Can you waterproof a leaking flat roof?
Yes. We repair the existing covering or replace it with felt, EPDM rubber or GRP fibreglass, depending on its condition.
Will a coating stop my roof leaking?
Sometimes for a while, but coatings and sealants are rarely a lasting fix on their own. Renewing failed lead, mortar or coverings lasts much longer.
Is my damp coming from the roof?
If it's near the top of a wall or on a ceiling and gets worse after rain, the roof, gutters or chimney are likely causes. We'll check and tell you.
Do you waterproof commercial roofs?
Yes. We work on offices, shops, warehouses and industrial units as well as homes.
Are your quotes free?
Yes. Call 07742 720 236 for a free quote.
Roof letting water in?
Call Danny on 07742 720 236 or request a free quote. We cover Preston, Leyland, Chorley, Penwortham and the surrounding area.