THE HOME DETECTIVE

23/01/202524/06/2026

Rain and Stormwater Management

The Vital Importance of Proper Rain and Stormwater Management Around Your Home’s Foundation

Managing rain and stormwater effectively is a critical yet often overlooked aspect of home maintenance. Rain and stormwater, pooling on paving, gardens, and lawns, near and against the house, can pose severe risks to the plinth and foundation footing. Therefore, understanding these risks and taking preventative measures is essential for maintaining the structural integrity of your home.

Rain and Stormwater Management Prevents Structural Damage

The foundation footing is your home’s backbone. Excessive moisture around it can weaken the supporting soil, causing it to erode and destabilise. This can result in uneven foundation settling, leading to cracks in walls, floors, and ceilings. The plinth, which acts as the transitional layer between the foundation footing and the superstructure, is particularly vulnerable to water damage. In addition, moisture can seep into the plinth, causing it to deteriorate and compromising the stability of the entire building.

Avoiding Dampness and Mould Growth

Rain and stormwater pooling around your home create the perfect conditions for mould and mildew to flourish. Mould poses significant health risks, such as respiratory problems and allergic reactions. It can also lead to extensive damage to building materials. Mould spores can infiltrate walls, floors, and furniture, necessitating costly repairs and replacements. Moreover, directing rain and stormwater away from the foundation footing and plinth creates a dry environment that discourages mould growth, promoting a healthier and safer living space.

Extending the Longevity of Building Materials

Moisture is particularly harsh on building materials like concrete, plasterwork, and brick. Prolonged exposure to water can cause these materials to deteriorate prematurely. Concrete can crack and spall, and bricks can crumble and lose structural integrity. As a result, by ensuring that rain and stormwater are directed away from the plinth and foundation footing, you can significantly extend the lifespan of these materials. This not only reduces maintenance costs but also preserves the overall strength and durability of your home.

Protecting Your Gardens and Lawn, and Landscaping

Effective rain and stormwater management is also beneficial for your gardens and lawns. Pooling stormwater can oversaturate plant roots, leading to root rot and plant and lawn death. By ensuring proper drainage, you create a healthier environment for your plants and lawn to thrive. Additionally, a well-drained garden and lawn prevent excess moisture from seeping into the soil around your home’s foundation footing, reducing the risk of structural damage.

Implementing Practical Rain and Stormwater Management Solutions

Several practical solutions can help you manage rain and stormwater effectively and protect your home:

Gutter and Downpipe Maintenance: Regularly clean and maintain gutters and downpipes to ensure they direct rainwater away from the house. Install downpipe extensions to carry rainwater farther from the foundation footing.
Grading: Ensure the ground around your home slopes away from the foundation footing. This natural drainage technique (swales) helps divert rain and stormwater away from the house.
Sub-soil Drains: Installing sub-soil drainage in problem areas around your property can efficiently channel rain and stormwater away from the foundation footing. These drains consist of perforated pipes buried in the ground, allowing water to flow away from the house.
Rainwater Harvesting: Collecting rainwater in tanks can help reduce the amount of rain and stormwater pooling around your home. This water can be repurposed for gardening or other outdoor uses.

Conclusion

In summary, keeping rainwater, stormwater, and pooled water away from your home’s plinth and foundation footing is essential for preventing structural damage, avoiding dampness and mould growth, extending the longevity of building materials, and maintaining a healthy garden and lawn. By implementing effective rain and stormwater management practices, you can protect your home, ensure a safer living environment, and safeguard your investment for the long term. Proper rain and stormwater management is not just about preservation but proactive protection for your home.

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THE HOME DETECTIVE » stormwater problems

14/03/201922/07/2025

Damp In Freestanding Walls

Do Your Boundary Walls Look Like This?

This photo I took during a client’s comprehensive buyers inspection had rising damp, falling damp and penetrating damp in the boundary and garden walls. In addition, the white marks on the wall were caused by efflorescence.

Often the maintenance of the walls that are attached to or which do not form part of our houses is neglected. These are our boundary, garden and courtyard walls.

These walls are very important in that they protect our privacy and security and are our first line of defence against intruders. Unfortunately, we sometimes do not make enough effort to protect them!

The greatest enemy of these walls is damp which penetrates into the wall from below, above and from the sides of the walls.

Rising Damp

Rising damp occurs as a result of capillary action at and below ground level into porous building materials. These materials are mainly concrete, bricks and mortar. The moisture rises up the wall in this way. It usually occurs where there is no damp proof course (DPC). Freestanding walls such as boundary and garden walls do not normally have DPC built into the walls because it would make the wall unstable. A layer of DPC would break the bond between the wall and its foundation.

The height to which the moisture will rise is determined by the evaporation rate and the nature of the wall. However, the normal limit for rising damp is generally about one metre above ground level.

Rising damp may show as a stain on the plastered and painted wall, the blistering of paint and loss of plaster. A damp area may be evident at the base of walls and in extreme situations, may cause the structure of the wall to wear away and crumble.

Falling Damp

Falling damp is caused by downward water penetration from the top of porous masonry walls. This is as a result of the top of a boundary wall not being adequately waterproofed, if at all.

Walls should be:

properly sealed at vertical expansion joints;
repaired at copings that have cracked or deteriorating mortar joints;
cleaned to prevent the build-up of dirt and moss on upper surfaces of stone or brickwork.
Leaves, bird manure, moss and dirt on top of the walls contain weak acids and salts which can promote decay of the masonry and paint if absorbed.

Penetrating Damp

Penetrating damp is a common form of damp. It occurs as a result of the horizontal ingress of water through gaps, cracks and joints in the wall’s structure. Penetrating or horizontal damp can be due to your or your neighbour’s irrigation system spraying against the boundary wall. Moreover, foliage growing against the wall (bushes and trees)can also be the cause. Other causes are deteriorating paint finishes and inadequately ruled joints which allows moisture intrusion into faced brick or stone walls.

Penetrating damp tends to produce localised patches of dampness and decay, whereas rising damp may affect the base of the wall.

Efflorescence

Efflorescence occurs when an appreciable quantity of soluble salts and moisture is present in the masonry. It routinely occurs in masonry construction, particularly in brick and concrete. It typically occurs during the initial curing of the cementitious product. Moisture carries these salts to the face of the masonry or concrete where the moisture evaporates.

As the water evaporates, it leaves the salts behind as a white fluffy deposit. Therefore, to remove it, brush the deposit off when the wall is dry. It usually disappears with time after rains or washing with water.

Efflorescence is generally an aesthetic concern and not a structural one. However, where there is excessive efflorescence, the crystallizing salts within the pores of the masonry can disrupt even the strongest material. As a result, this can lead to the breaking up and crumbling of the structure.

How to prevent damp damage in your freestanding walls

Rising Damp

Rising damp is not easy to resolve in any freestanding, boundary or garden walls because of the lack of DPC. However, you can do the following:

Make sure that there is no pooling of water against the wall. Good drainage away from the walls is essential. If you have a low point in your garden against your boundary walls you will need to create a hole in the wall at the lowest point for the stormwater to drain away. Your neighbours have to accept a certain amount of your stormwater by law.
Try not to overwater your gardens against boundary and garden walls. overwatering will result in sodden earth around the walls and, as a result, rising damp in the wall.
Keep leaves and other debris on the ground which may retain water away from the walls.

Falling Damp

You should waterproof the tops of all freestanding walls with a layer of an acrylic waterproofing system or any other system to prevent moisture intrusion into the top of your boundary and yard walls.
If there is a concrete or brick coping on top of the wall you must ensure that the joints form a water-resistant seal. You should seal all deteriorated joints or porous joints between the bricks and copings.
Seal the top of expansion joints to prevent water from entering the joint with a silicone sealer.

Penetrating Damp

Check the paint finish regularly on your boundary and garden walls. It may be time to repaint if the finish is chalky.
If you have a sprinkler system make sure that you are not watering your boundary walls. Sprinkler heads are normally adjustable. If yours are not, change them.
Trim bushes and shrubs so that there is a gap between the foliage, branches and the walls.
If it appears that the moisture is from your neighbours’ sides, you will need to talk to them about the problem.
Clean out and seal vertical expansion joints with a good silicone sealer. Any cracks should be sealed as well. Furthermore, if your plastered walls are covered in crazing cracking wash the wall down. Thereafter, when the wall is dry, seal the wall with a sealer and repaint the wall.

Efflorescence is a sign of damp

Efflorescence is caused by moisture absorbed in the wall evaporating and leaving behind salts as a white powder. Therefore, if you repair and maintain your walls as suggested above, very little efflorescence should appear on your walls.

I am not specifically promoting Prominent Paints as all the well-known paint manufacturers produce the same required paints and sealers. You can use most of them to repair and maintain your freestanding walls.

However, Prominent’s video provides very good advice on how to repair moisture damage to boundary and garden walls!

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THE HOME DETECTIVE » stormwater problems

22/11/201830/01/2025

Stormwater

Homes without Gutters and Downpipes

Stormwater management in the form of gutters and downpipes or perimeter paving is essential. This protects every home’s foundation and structure.

If you are like many homeowners, you have probably wondered why some houses have no gutters and downpipes to protect against stormwater damage. You may have wished your home had none because of the cleaning and maintenance issues.

Gutters and downpipes are not required by law on a sloping roof. Many modern homes have none, even in instances where they would benefit from having them. There are alternatives that architects sometimes prefer such as concrete paving around the perimeter of your house.

To decide whether rainwater gutters and downpipes are necessary for your home, it is best to see what the building regulations require.

The Building Regulations do not require roof gutters and downpipes if another suitable means of drainage has been provided. This is to remove or disperse rainwater from the roof away from your home.

However, the Building Regulations do require that any stormwater that flows from your roof or any area near your home must not cause damage to the interior of the building, its structure or its structural elements. The regulations require steps to ensure that stormwater does not accumulate. This is to avoid “undue inconvenience” to you as the occupant of your home.

Furthermore, the system used must:

not undercut the foundations by erosion or flooding
drain stormwater away from your home
not allow stormwater to accumulate against or close to the external walls
make provision for the drainage of any areas on the property where water pools
be capable of being easily maintained and cleaned