Can an Aerial or Satellite Dish Damage a Roof?

How a dish ends up damaging a roof

The dish itself is light, but the mounting turns it into a lever. A dish has a flat face that catches the wind, and every gust pushes against the bracket. If the bracket is attached to something weak, the force goes into that weak point. The three most common routes to damage are fixings through the roof covering, brackets on chimney stacks, and cables.

Fixings through tiles and felt

Some installers bolt a mounting through the tiles into a rafter or a batten. The bolt makes a hole in the tile, and in the felt beneath, and even with a bead of sealant, that hole is a route for water. Over a few winters the sealant dries, shrinks and cracks. The water then runs down the bolt into the loft and appears as a stain. The tile can also crack where the bolt is tightened, because clay and concrete tiles are brittle and do not like point loads. If the bracket is on slate, the slate can split across the fixing.

Look for a patch of staining on the ceiling below the dish, a dripping noise in the loft after rain, or a brown ring on the underside of the roof timbers near the bolt. A leak near the dish usually means this. How leaks like this are traced is covered in finding and fixing a roof leak.

Brackets on chimney stacks

Many aerials and dishes are strapped to the chimney, because it is high and clear of obstruction. A chimney stack is brick and mortar standing on its own above the roof, and it is already exposed to wind and weather. Adding a dish and a pole adds weight and wind load. The straps and lugs bite into the mortar, and the dish rocks in gusts, working at the joints. Over time the pointing cracks and the bricks loosen. In the worst case, part of the stack leans or falls. A chimney with a dish on it that is leaning, cracked or shedding mortar needs prompt attention, since falling bricks can injure people and damage the roof. A related guide on storm damage to roofs lists signs to watch for after high winds.

Cables and cable routes

Cables run from the dish down the roof and into the house. A cable pinned across tiles with clips can rub through lead, work under a ridge tile or sit in a gutter. Holes drilled through walls or soffits for cables should be sealed, and cables passing through the roof space should not rest in water. Loose cables also flap in wind and wear on the covering.

Signs to look for

From the ground, check for a dish or aerial that leans, a bracket that has rusted, mortar dust on the roof below a chimney mount, or a cracked tile near the fixing. Inside, look for a stain under the mount. Cables that hang loose or swing in wind are worth tidying before they wear a hole in the covering.

Dishes that are no longer used

Many roofs carry dishes and aerials that no one uses. Left on a roof, they continue to catch the wind and rust at the fixings. Removing one properly includes making good the holes, which an installer who just unbolts the dish often forgets to do. If you are removing a dish, ask for the fixing holes to be repaired and the tile replaced.

Putting a dish in the right place

Where possible, mount dishes on a wall or on a purpose-made mount, not through the tiles. A wall bracket on masonry avoids the roof covering entirely. If a roof mount is unavoidable, it should be fixed to the structure, with a flashing or a purpose-made tile that seals around the fixing. Listed buildings and conservation areas may have restrictions on where dishes can go, so check with your council before installing one.

What we do

We look at the area around the dish, photograph the fixings, check the tiles, the felt and the chimney, and tell you what we find. A cracked tile is replaced and a fixing hole sealed with a proper flashing, and loose pointing on a stack is raked out and repaired. If the dish is unwanted, we can remove it and make good. A fixed price in writing follows the survey. Our emergency and general roof repairs hub covers the type of work.