Finlock Concrete Gutters

If you have Finlock concrete gutters you probably know how much trouble they can be. Heres our guide to dealing with concrete gutters cost-effectively.

Finlock gutters, (often known as concrete gutters) are constructed out of a series of profiled concrete blocks that together create a rainwater channel along the length of your property. During construction they were laid on top of your walls with mortar in the same way as a brick or concrete block.

Finlock concrete gutters were used post war due to a shortage of steel which was traditionally used and they have been causing homeowners trouble ever since.

Why Do Finlock Concrete Gutters cause damp?

The 4 main weaknesses of finlock concrete gutters

1: Mortar Joints
The joint between each Finlock concrete gutter block is made of mortar. Over the years, the mortar becomes permeable and leaks water directly from the gutter channel into your walls.

2: Level along the run
Finlock concrete gutter blocks were laid level on a mortar bed, just like a brick. This means Finlock concrete gutters have no pitch or fall. It’s fitted level, therefore it cannot effectively shed rain water.

3: Sagging
Sagging can occur anywhere along Finlock concrete gutters, but is often most noticeable above your windows. The original windows were fitted when building the walls and the gutter blocks were then laid on top. The Finlock concrete gutter blocks above windows often have less support than those resting on solid brickwork. This results in sagging outward above the windows causing dips in the run. These sagging dips hold water, leaving puddles in the gutter. This is known as ponding. Each of these ponds is a reservoir of water that will continue to leak into your home long after it stops raining.

4: Cold bridging
Each Finlock concrete guttering block is continuous from its overhang outside, to the inside wall of your home. If it is cold outside, heat is lost directly through the damp Finlock concrete guttering. This creates a cold spot at the top edge of your upstairs wall. When a house has been upgraded with draught proofing, double glazing, cavity insulation and modern central heating, these spots at the top of the walls become the coldest surfaces in the house. This causes all the condensation from the home to settle in these already problematic areas.

What should I avoid?

Do not attempt to seal or line your Finlock concrete gutters. It’s a waste of money, Period. It’s tempting due to the difference in cost. However you will soon be paying for it to be done again. Sealing or lining does not work! It will not solve your leaks. It will not solve your sags. It will not solve your damp!

What should I do?

Remove the Finlock concrete gutters and install a uPVC fascia soffit and guttering system.

This will:

1: Create a guttering that overhangs the property: This means the rainwater is collected outside of your walls, (not partially above the walls like with Finlock concrete gutters).

2: Create a guttering system with a fall: This just means that the guttering leans in the right direction. This channels rain water away quickly and stops all ponding.

3: Stops cold bridging and creates thermal efficiency: uPVC is know for is insulative qualities, and your cold, damp, Finlock concrete gutters are removed.

4: Creates a lightweight roofline: It will not sag under its own weight or suffer from ponding.

If you have any questions please feel free to comment below.