Damp In Freestanding Walls

Do Your Boundary Walls Look Like This?

damp in walls

This photo I took during a client’s comprehensive buyers inspection had rising damp, falling damp and penetrating damp. 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 masonry building materials. These material 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. 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;
      • 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 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 or foliage growing against the wall (bushes and trees). 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 is where an appreciable quantity of soluble salts 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. This deposit can normally be brushed off when 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 maintain your freestanding walls

Rising Damp

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

      1. Make sure that there is no ponding 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.
      2. 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.
      3. Keep leaves and other debris on the ground which may retain water away from the walls.

Falling Damp

      1. 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.
      2. 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.
      3. Seal the top of expansion joints to prevent water from entering the joint with a silicone sealer.

Penetrating Damp

      1. If your freestanding walls are plastered, check the paint finish regularly. It may be time to repaint if the finish is chalky.
      2. If you have a sprinkler system make sure that you are not watering your boundary walls. Sprinklers heads are normally adjustable. If yours are not, change them.
      3. Trim bushes and shrubs so that there is a gap between the foliage, branches and the walls.
      4. If it appears that the moisture is from your neighbours’ sides, you will need to talk to them about the problem.
      5. 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 caused by moisture absorbed in the wall evaporating and leaving behind salts in the form of a white powder. Therefore, if you repair and maintain your walls as suggested above you should have very little or no efflorescence appearing on your walls.

I am not promoting Prominent Paints as all the well-known paint manufacturers have the paints and sealers that you can use to repair and maintain your freestanding walls.

However, there is very good advice in the following video by Prominent Paints on how to repair boundary and garden walls if they look like the photo above!



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High Water Bills



Your high water bill could be due to either a temporary increase in water usage or a leak. To find out if it’s a leak, first shut off all your water-using fixtures in the house.

Take the cover off your water meter box and flip open the protective cover plate on the meter dial. Normally, your metre box will be somewhere along the front property line, often near a corner. You may have to dig down a little in the dirt to find it.

The meter may be a newer one that has a small round or diamond-shaped low-flow indicator near the centre. The low flow indicator may be red or black like in the photo above. It should not be turning. But if it is, there’s a leak somewhere in your plumbing system. At a meter without a low-flow indicator, note the meter reading or take a picture with your cellphone. Check back in an hour or so and see if it has changed.

There are a number of places to check if the meter says you have water flow indicating a leak:

  • Leaking Taps

Not just the at the sinks. Also check the taps at the washing machine hookup, water heater, tub/shower, and the outside hose taps.

  • Leaking Toilet Cisterns (tanks)

A flapper valve that doesn’t seat properly at the bottom of the cistern will cause a leak. Check the ballcock arm and overflow tube as well, it may also be defective. Drop a dye tablet (available in most hardware stores specifically for toilet testing) in the tank. Do not flush, and wait for 15-minutes. If the colour shows up in the bowl, the toilet needs repair.

  • TPR Valve at the Geyser

The small valve with a flip-up handle at the top or side of the geyser called a Temperature and Pressure Release valve. This important valve is designed to open if the water gets too hot, to keep the tank from exploding. These valves sometimes fail by opening slightly and letting loose a slow trickle of hot water. The water normally runs in a steel or copper pipe to a location at the exterior wall. Find the termination of the TPR valve and check for a drip. NEVER work on these valves yourself! Only a suitably trained and experienced plumber should!

  • A Leaking Water Pressure Regulator

You will usually find this valve where your water supply enters your house. Alternatively, it may be before the geyser on the cold water supply. A certain amount of water is discharged from the drip of the pressure regulator during the course of normal operation. This discharge is normally directed away from the foundation of your home with discharge pipe. It should discharge either into a gulley close by or directly into a sewage pipe. If the pressure regulator is in your roof a copper or steel pipe should run to the outside of an exterior wall. It may discharge into the gutter if your home has gutters.

If a pressure valve is leaking excessively, it is possible that the pressure valve is faulty. It means the pressure in the geyser and its pipes may be too high. Additionally, an excessive leaking pressure valve can lead to large increases in water usage. Put a bucket under the discharge. If its leaking more than 5 litres per day replace it!

  • Geyser Tray Discharge

If water is dripping out of the geyser tray PVC pipe It could mean your geyser has sprung a leak. The leak could be at the geyser drain valve or the geyser itself. For whatever reason, it does mean you have a problem that requires the attention of a suitably qualified plumber.

  • A Leak Under the Floor Slab

These are the hardest to detect until they get really bad. Walk around the perimeter of the home and look for any muddy areas at the base of the walls. Also look for any areas where the soil has washed away at the wall or paving, creating a hollow. Wet spots in the floor and moist, discoloured skirtings are another clues.

  • Leaks Between the Water Meter and the House

Again, leaks here are difficult to detect until they become gushers and water starts bubbling up out of the ground. But some homes have a secondary water shut-off valve in the ground, usually where the water supply enters the house. If your house has one. If the meter continues to show water flow then your problem, or part of it, is underground in the yard.

Galvanised waterpipes tend to fail prematurely because they eventually rust. Although fine for underground and cold water installation, Polycop fails fairly quickly if used for hot water systems. Also, copper pipes can deteriorate early when the water is especially acidic. Furthermore, copper pipes are easily damaged. So also take into consideration the type of piping you have. And, when all else fails, call a good plumber.

Lastly, it can be a combination of small leaks that are sending your bill so high!

When I do your Maintenance Inspection I will check your water system as well!

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Efflorescence is one sign that is often dismissed as just being an eyesore and is given surface treatment only.  This is the presence of the white powder that forms on the face or surface of concrete, plasterwork and brickwork.

It is a cause for concern!


Efflorescence is a build-up of minerals and salts on the surface of the concrete, brick and plasterwork due to repeated bouts of excess water in the material. The minerals and salts that naturally occur in the material are dissolved when the brickwork, plasterwork or concrete is waterlogged with water.

Concrete, pavers, brickwork and plasterwork are porous and can absorb or wick water and draw salts to it like a tree transports water from its roots to its leaves. This is capillary action. When efflorescence happens, it can indicate a moisture issue that could potentially damage the structure.

When water reaches a building material’s surface, evaporation will occur. Water absorption and wicking will continue after the water evaporates and the salt is left behind. This eventually creates a high salt concentration, leading to osmosis.

What is Osmosis


Simply put, osmosis in building materials is the movement of water from a region of low salt concentration to a region of high salt concentration in the material.

During osmosis, when water moves toward salts and minerals to reduce its concentration, it can cause large hydrostatic pressures within the porous building material. As a result, these pressures can damage or destroy the material.

Osmosis can cause pressure that ranges up to 200 bar, exceeding the structural strength of concrete. Therefore, osmosis may result in porous building material cracking, flaking or falling apart.

While the efflorescence is only a cosmetic problem in itself, its appearance on the wall indicates an ongoing water intrusion problem.

That means if you notice efflorescence on any concrete, plasterwork, brickwork and other structures, it’s important to take action by finding and eliminating the source of the moisture intrusion.

Most Common Causes of Efflorescence


  • Garden irrigation systems:

One common cause of minor efflorescence is a sprinkler head that sprays on the walls of the building.

  • Frequently wetted areas:


Repeatedly washed and wetted concrete can form efflorescence, such as a garage floor, stoop or paving.

  • Leaks in walls:

A leaking water pipe or waste pipe in the wall of the building may cause efflorescence both internally and externally.

  • Condensation:

Water may accumulate within a wall as a result of condensation. Things that take place inside such as cooking, bathing, washing and other actions employing water internally causes condensation. During cold weather, building interiors heated to normal comfort settings may contain enough moisture to cause condensation on cooler walls or on the underside of ceiling and roofing materials.

  • Contact with the ground:

When brickwork, plasterwork and concrete are in contact with the earth, groundwater may be absorbed by the material. Moisture may rise through capillary action several feet above the ground. This may occur in the building’s plinth brickwork and columns if there is water ponding against the plinth. Efflorescence also often occurs on the bottom of retaining walls.

  • No roof drainage:

Lack of roof drainage such gutters and downpipes will allow rainwater pouring off the roof to splash up against the walls. This can cause moisture intrusion into the walls and efflorescence on the walls. The bubbling of the painted and plastered wall finishes will result.

  • New buildings:

A new building will sometimes have a minor efflorescence bloom. The moisture still in the material from the building process is evaporated away during the first months following construction.

  • Freestanding structures:


Chimneys, freestanding walls and parapet walls on balconies and roofs are the most susceptible. Often they have not been properly waterproofed or not waterproofed at all. They will most likely show signs of efflorescence in the top section of the wall.

  • Water Ponding:

Water ponding on brick and concrete paving will cause efflorescence.

  • Defective installations:

Roof leaks and leaks around windows and doors may cause efflorescence on the structure of the building.

Some of the best ways to remove efflorescence include:


  • Pressurized Water:

Applying a strong jet of water may dissolve efflorescence quickly. If you use water, dry off the water from the building material after application. If you fail to remove the water, salts may remain that can cause efflorescence to reappear.

  • Diluted Vinegar:

You can use diluted white vinegar on efflorescence. It’s less harmful than industrial chemicals. You most likely already have vinegar in your kitchen.

  • Brushing:

With a strong brush, you can remove efflorescence with ease.

Removing efflorescence can be quick and simple. In fact, efflorescing salts are water-soluble, which means efflorescence may disappear on its own due to normal weathering.

What can I do about efflorescence?

The fact that water has penetrated the structure is the root issue.  Furthermore, the moisture intrusion will likely be the cause of the eventual repair or replacement work that will be required.

Efflorescence is associated with potentially severe underlying complications. Therefore, it is highly advisable to seek expert advice to determine the source of the moisture intrusion causing the efflorescence.

If you have an efflorescence problem or suspect there may be a leak somewhere in your home, it’s wise to call me before you call a repair company. Repair companies have a vested interest in getting work. As a result, you have to careful in accepting what they say requires repair or replacement.

I provide an unbiased opinion. I have no gain out of the evaluation of things that need repair (e.g., your roof or foundation).

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Sealing at Windows and Door Frames

Detecting Leaks Around Your Windows

seal leaking

Seals which are broken, pulling away, missing or which are damaged as a result of ageing or long-term weather exposure will cause windows and doors to leak. Furthermore, the sealant or window putty used to seal the glazing beads on wooden windows may crack and allow moisture into the gazed areas of your windows. In addition, when the glazing putty on your steel windows cracks or a section falls out moisture will corrode the steel window frame.

These are the most obvious areas where leakages occur!

However, the most undetected area for leaks at windows is the junction between the window frame and the brickwork, plasterwork and window sill. As a matter of fact, it is one of the most common defects that I have found on both new and older homes.

There are multiple ways to detect leaks around your windows and doors:

  • On the outside of your home, check the areas where two different materials meet. This includes your door and window corners and frame.
  • Look for cracks in the door itself and in window panes.
  • Examine the existing caulking (sealing) and window weather stripping and weatherboards on doors. Make sure both are in good condition. In addition, leave no gaps or cracks.
  • If you can see daylight around a window or door frame, there will be a leak.
  • Shut a window and check for gaps in which you can insert the paint scraper. If you can easily insert the scraper under the closing part of the window, it is probably not watertight!

Types of Window Caulk

The sealant used to seal windows is the caulk. Furthermore, caulking is the action of sealing the windows doors and so on. For one window, homeowners will likely use a half-cartridge of caulk. Also, be sure to use a UV resistant caulk for external caulking. Similarly, you will need to use an acrylic caulk if you are sealing around the edge of the frame on plastered and painted homes. Additionally, your local hardware or paint supplier will be able to give you advice on the different caulking materials you should use for differing applications.

Seal the Cracks and Leaks

Once you’ve selected the best caulk for your home, follow these best practices for sealing:

  • Clean areas to be caulked. Remove old paint or sealant. Use a putty knife, screwdriver, or a rough brush to clean the area.
  • To avoid sealing in moisture, make sure the area is dry. In addition, it is better to apply caulk during dry weather with low humidity.
  • Apply caulk to all joints in the window frame, especially the joint where the frame and walls meet.
  • Hold the gun or product at a 45-degree angle, and caulk in one continuous movement.
  • Make sure the caulk sticks to both sides of a crack.
  • If caulk comes out of a crack, use a putty knife or screwdriver to remove it. Reapply the caulk in the crack after making sure that the area around the crack is clean.
  • Check the window sill for cracks in the plaster and mortar joints especially between precast window sills and seal them.
  • Caulk the top edge (head) of the window frame. It will prevent moisture from running back along the underside of the lintel and entering the windows frame. If you don’t seal this area moisture can become trapped behind the frame and lintel.

Be Careful Where You Seal

It may be tempting to seal any and all gaps around your windows. However, some windows require the means to prevent moisture from accumulating in the frame itself.

Avoid caulking:

  • The window’s weep hole.  This small hole at the bottom of the window frame which allows moisture behind the window to exit through the frame. Therefore, if you plug this hole, it could cause mould or rot to grow unchecked.
  • Don’t seal moveable parts. Caulking moving parts could seal your windows closed. Therefore, avoid affecting operable parts, like sashes in a double hung window.
  • Be careful with caulking above the window frame.  A groove in the plasterwork at the top of the window along the width of the window is a drip. It helps usher rain away from the windows frame. As a result, closing off this joint can allow moisture to become trapped behind the frame and lintel.

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Walk-Through Inspections

Walk-Through Inspections

walk-through inspection

About Walk-Through Inspections

A walkthrough is not a general home inspection.  It is a much more informal inspection than my usual property inspections. As a result, I perform a visual walkthrough of the home/building and provide you with comments summarizing my observations. Furthermore, my comments will be nothing more than a subjective summary of my initial observations during the walk-through.

A walkthrough is also very affordable. This type of inspection is mainly for a client who does not (at this point) want a full home inspection. Because a walkthrough is less formal, I do not adhere to the InterNACHI Standards of Practice. If you are present at the walkthrough I do not generate a written report.  I communicate my observations orally to you.

However, you don’t have to be present during the walkthrough.  If you are not, I will generate a checklist during the walkthrough by using specialised software for your information.

However, we will need to have a Walk-Though Inspection Agreement with each other. This is to protect me against liability as a result of deviating from the requirements of InterNACHI Standards of Practice.

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