5 Signs That Your Timber Windows Require Replacement

1. Your windows are rotting.

Timber as a material is susceptible to rot and decay if it has not been treated or sufficiently maintained. There are two types of rot that may occur to timber, these are wet and dry rot. Both wet and dry rot occur when timber is exposed to higher levels of moisture for a sustained period of time.

Wet rot often occurs where moisture conditions are higher and can take place to both poorly ventilated and well-ventilated areas. Wet rot is fairly simple to identify as the timber will appear wet and flaky.

Dry rot, whilst sounding less damaging is much more of a concern than wet rot. If identified, dry rot must be treated with urgent care as it has the ability to grow through thick walls in search of further moisture and timber nutrients. It is widely accepted that dry rot requires a moisture content in excess of 20% and thrives in poorly ventilated conditions. Dry rot sucks the nutrients out of timber causing it to decay and lose its structural integrity which is why it is widely regarded as more damaging than wet rot as it can contribute to structural failure. The below photo demonstrates how dry rot may look in the later stages.

The extent of damage should be assessed on a case-by-case basis as to whether rotted timber can be repaired or requires replacement. Splice repairs may be required where repairs are appropriate and in the event that dry rot has affected your property, it is recommended that you seek professional advice from a building surveyor to understand the source of moisture and put measures in place to prevent the rot from reoccurring. It should be noted that you may also need advice from a structural engineer depending on how the affected timber contributes to distributing loads.

• Your windows are not energy efficient

Often older timber windows use single glazing which can mean that they are not particularly energy efficient. This often results in significant heat loss through the windows in your home meaning your household bills will be higher.

Single glazed windows often cause condensation due to the difference in temperature between the outside and inside air which is especially prominent in winter for this reason. Condensation can lead to mould which may impact the health of those living in your home. When condensation forms on your windows, it increases the chances of rot occurring based on the higher levels of moisture and lower ventilation.

If your home has singled glazed windows, it is important to consider replacing your windows with double or triple glazing or seeking to add a secondary glazing to your existing windows.

• Your windows are difficult to operate

Due to timber being a natural material, it has the ability to change in volume based on humidity levels. Over many years, the shrinking and swelling can cause the windows to warp making stiff and difficult to open and close.

Older timber windows will often have been painted a number of times during renovation projects and general maintenance, this can mean that they often stick and require some force to open and close. If this is the main problem with your timber windows, it may be worth stripping back the paint, making good and reapplying a suitable paint to resolve this issue.

Other key issues making it difficult to operate timber windows include defective hardware, buildup of dirt and debris, dried out weatherstrips and many more.

• Your windows have insect damage

Insect attack can be a fairly common issue with timber components, there are many different types of woodboring insects that seek to attack the timber. Insects attack different types of wood due to their nutrients that they feast on.

Depending on the type of wood boring insect, damage occurs through small holes that range from 1mm-10mm. BRE Digest 307 provides details on the different types of wood boring insect, their characteristics and the necessary remedial action.

The remedial action for insect attack is as follows:

• Locate timbers demonstrating characteristics of insect attack
• Understand the type of damage
• Understand the extent of damage
• Treat infestations if active and deemed necessary

• Your windows have failed joints

Water leakage between glazing and the window frame can be common, this will often occur due to the following reasons:

• Poor glazing installation
• Faulty beads
• The opening far exceeds the size of the glazed panel
• Inappropriate bedding material
• Leakage through joints

It is important that the extent of each of the above defects is assessed to understand if the windows can be repaired or if it makes more sense to replace the windows in their entirety. This may require appointing a building surveyor to assess the damage and provide advice. BRE Good Repair Guide 10 Part 1 (June 1997) provides an in-depth analysis on this subject and the necessary repairs that may be required.

Why replace windows with timber rather than UPVC?

You may ask yourself why not replace your existing timber windows with UPVC alternatives to avoid the defects listed above. There are some significant factors that should be considered before making the switch.

• Ventilation – Timber windows are quite drafty which provides ventilation, when replaced with UPVC which is a more airtight product, this can increase the likelihood of condensation and mould in the colder months.
• Character – The construction of timber windows involves a higher level of craftmanship and it is quite easy to tell the difference between timber and UPVC even with the technology we use today.
• Planning – There may be restrictions for use of timber windows to be replaced. On our previous projects, where the site is considered of historical value such as conservation areas and listed buildings, the planners require the windows to be replaced with the same material and in keeping with the existing appearance.
• Quality – We believe that the quality of timber is better than UPVC. In character buildings, it seems the best option to replace like for like but should be noted that these will require more maintenance.

Conclusion

In conclusion, understanding the potential defects and signs that your timber windows require maintenance or replacement is crucial. Whether your existing timber windows are showing any of the above signs, it is important that you take regular care of your windows and understand the maintenance requirements. You must weigh up whether your windows can be refurbished or require complete replacement and it is best to seek advice from a building surveyor if it is not completely clear.

Author: Henry Blanks – Oaklea Construction