Troubleshooting Problems with Your Lightweight Conservatory Roof

Lightweight tiled conservatory roofs are a brilliant upgrade — when they're installed properly. When they're not, you can end up with leaks, condensation, sagging or a room that's still uncomfortable to use. Here's how to diagnose the five most common problems we get called to in Plymouth and across Devon, and what each one actually needs.

Problem 1: It's leaking

The four likeliest causes, in order:

• Blocked gutters. Water backs up over the wall plate and looks exactly like a roof leak. Always check the gutters first.
• Perished wall-plate sealant. Where the new roof meets the house wall. Re-sealing is usually £200–£400.
• Lifted lead flashing. Wind or house movement gradually lifts the flashing. Quick to spot, fairly cheap to re-fix.
• Poorly bonded ridge cap on budget systems. If the ridge isn't mechanically fixed and properly sealed, wind-driven rain works its way in.

See our deeper guide on identifying and fixing water ingress.

Problem 2: There's condensation

A small amount of condensation on a brand-new tiled roof is normal as the structure dries out for the first few weeks. Persistent condensation usually means one of:

• Inadequate roof ventilation — the system needs vents at eaves or ridge to let moist air escape.
• Missing or torn vapour barrier — common on rushed installs; warm humid air from the room reaches the cold side of the insulation.
• Insufficient insulation depth — the inside surface stays below dew point on cold mornings.

All three are remediable, but they need a survey to diagnose properly. See our conservatory condensation guide.

Problem 3: It's sagging

A properly engineered SupaLite roof shouldn't sag — every job is calculated to the specific conservatory and signed off by building control. Sagging on a budget tiled roof almost always traces back to:

• Undersized rafters (saving cost on timber).
• No structural strengthening of the original frames where it was needed.
• No engineering calculations submitted to building control.

If your roof is sagging, get it surveyed urgently. In some cases it's repairable; in others, the only safe option is full re-build.

Problem 4: The room is still cold

A SupaLite warm roof should achieve a U-value around 0.15 W/m²K — see our energy efficiency guide. If the room still feels cold, check:

• Was the specified insulation thickness actually fitted?
• Are the side windows still single-glazed?
• Is the floor uninsulated solid concrete with no underfloor heating?
• Are there draughts at the doors or wall-plate junction?

Problem 5: The finish looks rough

On a proper install, the inside finish is plastered, painted and lit with recessed downlighters. On budget installs you sometimes see exposed plasterboard joins, badly cut downlight holes, or visible service runs. All of this is remediable with a competent plasterer and electrician, usually £600–£1,200.

Got a problem with another company's install?

We regularly survey and remediate tiled conservatory roofs installed by other companies across Plymouth, Devon and Cornwall. We'll give you an honest opinion on what it actually needs. Request a free survey.