TIMBER TREATMENTS
Timber problems come in several forms. Timber may be attacked through both insect infestation or fungal decay caused by wet or dry rot. Insect infestation can be eradicated with insecticidal fluids, but fungal decay may require the removal of the most severely decayed wood and the preservation of the remaining timber to prevent the re-occurrence of fungal decay.
Dry Rot
Dry rot is a serious problem that can cause structural damage to properties if not resolved immediately. Dry rot (serpula lacramyns) is caused by a fungi that can grow on any unprotected timber or sub strata such as brick or plaster which has become damp. To treat dry rot, the source of damp needs to be addressed. Typical reasons for damp could come from rising damp due to a defective dampcourse or leaking internal plumbing, or even lateral penetration of water from leaking gutters and downpipes or defective external render.
If not treated dry rot can have devastating effects leading to structural damage as it has the ability to live unseen behind renders and under floors as it continues to grow and search for moisture. The fungus attacks the wood by drawing all the water content causing the timber to crack across the grain, which is woods main strength.
Woodworm
Woodworm is the term used to refer to the larvae of wood boring beetles.
Woodworm is attracted to damper wood with a water content from as low as 12% going all the way up to 30%. This is because the wood is easier for the larvae to digest when the wood is damp. Infested wood needs treating with a Lignum Pro D156 based solution, and as a precaution, you would be advised to treat all timbers in close proximity to prevent a further outbreak in the future.
CONDENSATION CONTROL
Condensation is caused by a lack of air circulation, combined with cold exterior walls. The most effective method of condensation control is by the installation of a home ventilation system.
Condensation occurs when the water content of air rises above the level called the ‘dew point’, at such time, water droplets will form on the coldest surfaces e.g. windows and external walls, etc. On average, a family of four people will produce about two gallons of water vapor per day from activities such as cooking, bathing, breathing, and the washing and drying of clothes. It is also a fact that nowadays most properties are insulated to prevent warm air from escaping, this reduction in ventilation, allows the air contained within the property, to reach relative humidity. In such cases, it may be necessary to install fan units in either roof voids or walls which draw in fresh air from outside, and each room is slightly pressurised and the continual air movement eliminates any stagnant pockets of moisture-laden air, which is eventually expelled through natural leakage points (window and door crevasses, flues and grilles, etc.)
Some of these fans can be set to alternate between drawing in air and expelling air.
Condensation is not helped by modern living. We are all told to save energy and save money but saving money has meant that condensation has increased in many households. How often are windows opened to vent the rooms? How many people dry clothes on radiators? This is the reason these fans are commonplace in our homes today.
Below are two examples of fans that we may use to combat your condensation.
RE-PLASTERING
In common with all remedial damp proof systems, the adequate removal and correct re-plastering of internal salt contaminated plaster is an essential requirement.
CHEMICAL INJECTION
Chemical Injection is the usual form of eliminating the Rising Damp, by drilling transfusion points into the affected walls at a low level and injecting a water-repelling cream by means of a simple applicator gun into the holes.
Rising Damp describes the movement of water through house footings by capillary action. The moisture dissolves soluble salts within the bricks and draws them up through capillary action from the ground level. The moisture dries as it gets exposed to the air on the surface and through this drying process, salts are left on or in the surface plasters. The salt deposits are harmless but leave a dust-like deposit, but in more extreme circumstances, a crystal formation (efflorescence) can be seen.
The action of removing these surface salts will not prevent them from returning. To achieve this goal, the defective render and plaster need to be replaced with sand and cement mixture containing a chemical salt retarder, to prevent the salts from migrating to the surface during the drying out period. Before any action is undertaken, you must first, establish where the source of the water is from. This can be from lateral water penetration from defective gutters, bad pointing, or the lack of an effective damp proof course.
If it is found the walls have a defective damp proof course, a new one needs to be installed. There are many reasons why the damp proof course may be defective. The house may be of an age where a damp proof course was not originally thought necessary, or the original Astos or slate membrane has broken down through time. Or if it has had a chemical injection course previously, it may have now been breached. Or the original damp proof course has been bridged with the introduction of raised earth or concrete drives and patios around the property.
The installation of a new damp proof course will require irremediable plaster on the affected walls to be removed to a height of at least 900mm and will comprise of drilled holes in the brickwork 50mm above outside ground levels to comply with current building regulations, this could depend on outside ground levels, mean that the area underneath the damp proof course, internally, will require treatment with tanking slurry (cementitious material) to prevent the lateral penetration of moisture through the wall below the new damp proof course. A new damp proof course consists of a series of holes that are filled with a silicone-based cream which spreads and creates an effective barrier. After which the walls will be re-plastered with a sand and cement render containing salt retarding chemical.
OVERSKIMMING
The term Overskim is used when an existing finish on a wall is plastered over, leaving a fresh newly plastered wall ready for redecoration.
This can be advantageous on poor, pitted walls that need repainting or have a textured finish on them. Not all walls are suitable for this procedure as the walls need to be sound and not hollow. Any hollow parts and cracks may need to be cut away and repaired before an application of thistle plaster can be applied.
The thickness of the plaster can vary from wall to wall, but the results can be outstanding. If a wall has a bow in it, it will have the same bow after over-skimming but will be left with a smooth finish.
If you require a Damp Proof Course, the existing plaster will need to be cut off to a height of 900 mm and then re-rendered with a salt retarding chemical. In such cases, the join from old to new will be seamless. However, many customers have expressed the desire to achieve the same smooth finish on the top of the wall as is on the newly replastered wall. In this instance, we would recommend an Overskim.
CELLAR TANKING
Properties with cellars, often unusable due to lateral penetration of moisture, can be treated to ensure a dry environment thereby giving further living space.