Why does my Garden Room and Garden Office get penetrating damp?

We tend to notice problems with damp during the wet and chilly times of the year, generally the autumn and winter months, although wet and chilly weather can also occur during the spring and summer months, as we in the UK know all too well! Garden rooms and garden offices often experience issues with damp and this can be caused by any number of reasons, including poor insulation, leaks, lack of ventilation and so on. Any owner who has experienced issues with damp in their garden room or garden office will tell you that it can be a nightmare to get rid of, in terms of time, effort and cost.  If you think that you may have a problem with damp it is vital that you get it diagnosed and treated as soon as possible, as any delay could result in damage to the walls, flooring, woodwork and decor of your garden room or garden office. If the damp issue is neglected and allowed to deteriorate it will be more difficult and costly to resolve, it can also pose a serious risk to the health of you and your family or your co-workers.

It is generally agreed that there are four types of damp that are commonly found in buildings across the UK, this includes garden rooms and garden offices. These four types of damp are – damp caused by condensation, rising damp, penetrating damp and the type of damp that results from leaks. This article is the third in a series of four in which we take a look at these common types of damp; the first article covered the problem of damp caused by condensation, please click here to view this article. The second article looked at rising damp, click here if you would like to view this article. This third article will cover penetrating damp, we will look at why it happens, the early signs of penetrating damp and how to identify and deal with it.

Why does Penetrating Damp Happen in Garden Rooms and Garden Offices?

Penetrating damp happens when moisture is able to enter a property by permeating through an external wall, window, door, or even the roof. Often simply called rain penetration, penetrating damp is also known as penetrative damp or lateral damp and it can affect any age or style of property, including garden rooms and garden offices. Any type of damp can become a serious issue if left untreated so it is important to get penetrating damp diagnosed and dealt with as soon as you notice the first signs of damp. Unfortunately, many of the symptoms of penetrating damp are similar to that of rising damp, this is why it is recommended that you call in a professional to get your damp issue diagnosed correctly. Generally, you will find that rising damp travels up to around a metre from the ground, hence its name – rising damp, whereas penetrating damp can occur anywhere on a building.

What are the tell-tale signs of Penetrating Damp in Garden Rooms and Garden Offices?

There are often many obvious and common signs when a building, such as a garden room or garden office is suffering with penetrating damp, these include the following:

  • Stains on internal walls
  • Stains on flooring
  • Signs of salts
  • Blistering plaster and paintwork
  • Crumbling or wet plaster
  • Damaged decoration
  • Mould
  • Signs of rot in timber, such as skirting boards and architrave
  • Damp patches on external walls
  • Damp areas on internal walls
  • Moss and algae growth
  • Damage to brickwork caused by spalling

As you can probably see from the above list, there are a number of common signs of penetrating damp that can also apply to other types of damp, this is what can often make it so difficult to diagnose the form of damp your garden room or garden office is suffering from. Unless you are absolutely certain of the type of damp you are dealing with, we strongly recommend that you seek professional help with the diagnosis, you will find that there are many reputable companies out there who offer this service at no charge, it is always best to get an accurate diagnosis so you can then treat accordingly.

Common causes of Penetrating Damp in Garden Rooms and Garden Offices

The occurrence of penetrating damp in garden rooms and garden offices can be caused by a number of reasons; unfortunately, some common and totally avoidable causes of penetrating damp are a lack of maintenance and bad design or workmanship. Here are some common causes of penetrating damp:

  1. Broken or missing roof tiles
  2. Damaged, deteriorated or poorly installed flashing
  3. Gaps around doors and windows due to poor installation or cracks due to damage or deterioration
  4. Broken, blocked or missing gutters
  5. Damaged or deteriorated external wall building materials, such as bricks, blocks or stone
  6. Damaged, deteriorated or poorly applied render
  7. Damaged, deteriorated or badly applied pointing
  8. Inappropriate or incorrectly installed cavity wall insulation
  9. Damaged pipework
  10. Lack of, deteriorated or badly applied weather or waterproof coatings or membranes
  11. External ground levels higher than internal walls
  12. Driving rain on porous masonry

How is Penetrating Damp Diagnosed in Garden Rooms and Garden Offices?

Unfortunately, misdiagnosis is common where damp is concerned and, because the tell-tale signs of penetrating damp in garden rooms and garden offices can be so similar to other causes of damp, it is often treated incorrectly. The wrong treatment means that the penetrating damp will not be dealt with so unless you are completely confident with your diagnosis, we recommend that you seek professional help. A survey will probably include the use of various types of electronic moisture detection equipment, such as a thermal imaging device, a moisture measuring unit that can be used in both search and measure modes, moisture probes, carbide meter, borescope cameras and hygroscopic salts detectors. A surveyor will also carry out a visual inspection and may take samples of mortar and any evident salts away for analysis to further assist the achievement of a complete and accurate diagnosis.

How is Penetrating Damp Treated in Garden Rooms and Garden Offices?

The good news is that some instances of penetrating damp in garden rooms and garden offices are relatively easy to deal with, for example, when penetrating damp has been caused by a broken or missing roof tile. The replacement of a roof tile can be carried out on a DIY basis, provided you can do so safely and have the required knowledge and equipment of course. Once the roof tile issue has been dealt with, you will need to check your roof space and anywhere else that the moisture has reached as the damp may well have caused further problems, such as rotting timber, degraded plaster, mould, etc., unfortunately, even a single broken roof tile can mean many other unexpected repairs will be needed. The replacement of roof flashing can also be carried out on a DIY basis, as can the repair or replacement of guttering and external pipes, however, these repairs should only be tackled in a safe way, with the correct equipment and by a competent person. If in doubt, always use a reputable specialist.

Once the repairs caused by defects or poor maintenance have been completed, your surveyor may recommend that the affected external walls are treated with some form of sealant to prevent further instances of penetrating damp, it is important to note that not all types of sealants will be beneficial as some will prevent your walls from “breathing”, this will simply seal the moisture within the building. Your surveyor or local damp specialist will be able to offer you advice regarding the best sealant to use.

It is important to allow your garden room or garden office to dry out once your damp issue has been resolved; heating, ventilation and the use of a dehumidifier will all help to speed up the drying out process but it could still take a long time. Redecoration should only be started once you are certain your building is completely dry.

To avoid any further issues with penetrating damp, it is vital that you carry out maintenance to all areas of your garden room or garden office on a regular basis, this will also help to avoid other forms of damp or unexpected repairs. The following areas should be inspected at regular intervals:

  • Roof – check the condition of your roofing material and any flashing or skylights for damage or deterioration
  • Gutters and downpipes – check for damaged or missing guttering or broken pipes
  • Doors and windows – check for cracks or breaks in glass, wood or UPVC, also check for gaps and fit sealant or draught excluder as necessary
  • Where brick or masonry sealant has been applied, follow manufacturers advice for further maintenance applications
  • Check pointing and repoint if required
  • Check rendered walls, patching and resealing where needed
  • Remove moss and algae growth
  • Remove wind dispersed seeded plants from cracks and the base of walls
  • Ensure woodwork receives yearly timber treatment or regular coats of paint
  • Clear drains of leaves and debris on a regular basis

Always carry out DIY repairs in a safe and controlled manner, using the correct equipment and following manufacturer’s instructions. Chemical sealants can be hazardous to your health and should be handled with extreme care, always follow the manufacturer’s instructions to the letter. We highly recommend that you employ the services of a reputable, professional specialist.

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