Signs your gutters are blocked (and what it costs if you ignore them)

The clearest signs of a blocked gutter are water spilling over the edge when it rains, plants or moss showing above the rim, and damp or green streaks on the wall below. Clearing a gutter is a small, routine job; leaving it can lead to penetrating damp, which Checkatrade puts at around £2,000 to treat on an external wall.

This guide covers what to look for from the ground, what a blockage does to your home, and what the repair bills look like if it is left.

The signs you can spot from the ground

You don't need a ladder to check. Walk round the house during or just after heavy rain and look for:

• Water pouring over the front or back edge of the gutter instead of running to the downpipe
• Grass, weeds or moss visible above the gutter line
• A gutter that sags or has pulled away from the fascia board
• Drips from joints, or a downpipe that stays dry while it is raining
• Dark, green or stained streaks on the brickwork or render underneath
• Splash marks, washed-out soil or standing water at the foot of the wall
• Birds or insects taking a lot of interest in one section

One sign on its own may just be a leaking joint. Two or three together usually mean leaves, moss and silt have built up and the water has nowhere to go.

What a blocked gutter does to your house

A gutter has one job: to carry rainwater away from the walls. When it is blocked, that water runs down the face of the building or sits against the timber and fixings at the roof edge.

Shelter lists faulty guttering alongside leaky roofs and cracks in external walls as a cause of penetrating damp, and notes that damp patches on external walls can be a sign of it (Shelter: damp and mould). Inside, that tends to show as a patch that gets worse after rain.

The roofline suffers too. The Federation of Master Builders lists visible rot or soft timber, water staining or damp patches, and sagging or leaking gutters among the signs that fascias and soffits need replacing (FMB: soffit and fascia replacement costs).

What it costs if you ignore it

The figures below come from published UK cost guides, not from our own price list, and every house is different. They are useful for a sense of scale.

• Penetrating damp: Checkatrade gives a typical treatment cost of around £2,000 for external wall damp proofing, with making good, such as plastering and painting, budgeted separately (Checkatrade damp proofing cost guide, updated June 2026).
• New fascias and soffits: the FMB quotes uPVC fascia boards at about £9.60 per metre and uPVC soffit boards from around £13.50 per metre, for materials only.
• Access: the same FMB guide puts scaffolding at anything from £200 for one side of a bungalow to £2,600 for a two-storey detached home.

Scaffolding is the part that surprises people. Once water has damaged the roofline, the cost of getting safely up to it can outweigh the materials.

When to check, and when to call someone

Late autumn, once the leaves are down, is the obvious time to check. Homes near mature trees in places like Quorn and Loughborough often need a second look in spring, when moss washes down off the roof tiles.

Call someone rather than waiting if:

• Water is running down a wall every time it rains
• A gutter is visibly sagging or coming away
• You have a new damp patch indoors on an outside wall
• The blockage is above a conservatory or extension you can't safely reach

Our guide on when to clean your gutters goes into the timing in more detail.

How Pure Flex clears gutters

Our gutter service clears out the leaves and moss so rainwater drains properly, and includes a check of the downpipes. It is carried out by the same fully insured, DBS-checked team that cleans your windows, and we work from our base in Sileby across the county.

You can book it as a one-off or add it to a regular window round, so it is done on a visit we are already making. See home exterior cleaning for everything we cover, or book online with a £10 deposit. Your exact price depends on the size of the property and access, and is confirmed in a free quote.