Introduction
Now that spring is in full bloom, all of the issues that have quietly been affecting your listed building’s joinery will make themselves known. Swelling, sticking, trapped moisture, and timber decay will all appear as if from nowhere, leaving you at a loss for what to do.
Joinery is one of the most vulnerable parts of a listed building given its exposure to both internal conditions and external weather, as well as the heavy use it sees. In this article, we will help you to identify problems in your joinery early on, understand why they can occur, and how to address these problems appropriately.
Why Spring Exposes Problems in Listed Building Joinery
Winters are cold, wet and dark. Moisture ingress can often go unnoticed or is dismissed as normal condensation because of the stark temperature differences between the inside and outside of the building. Add to this, the freeze and thaw cycles which can worsen woodwork and paint cracks, and may go unseen as we spend so much time indoors and have fewer hours of daylight.
When spring comes, it often brings an increase in temperature which can cause timber to move, suddenly making invisible damage very visible. It’s not that spring creates issues for listed buildings, just that we can finally see them in spring.
Swollen Sash Windows, Stocking Casements and Distorted Doors
Over winter, exposed timber will absorb moisture and expand. This can lead to windows being fused shut, sashes sticking, and casements not closing properly. Doors will be similarly affected and may drag, bind, or become harder to latch.
If you have warped timber doors or stuck sash windows, resist the urge to sand and cut these back as this can damage heritage joinery. Timber movement occurs when too much moisture is absorbed and the wood expands; by cutting back the timber to make it fit now, you will create gaps when the wood eventually dries and returns to its natural size. This will lead to draughts and dramatically reduce heat insulation and water protection. Additionally, sanding affected areas will remove protective paint and seals applied to the timber.
Paint Failure, Open Joints and Failed Putty after Winter
Peeling paint and gaps in putty are more than just a cosmetic issue; they are indicators of moisture problems with your joinery, which can lead to more costly repairs down the line.
Moisture-logged wood expands, as we know, and when it dries in the warmer weather, it shrinks back and can create open joints in glazing bars, cills, and frames. This in turn will let in more moisture, and worsen the issue.
By considering breathable paint and putty systems, you can reduce the moisture damage and may be able to avoid the cost of traditional joinery repairs altogether. Breathable paint and putty, unlike cheaper alternatives, will allow moisture to escape rather than trapping it and leaving it to soak into the timber.
Early Rot in Cills, Lower Rails and Concealed Wet Areas
Water tends to pool in certain areas such as cills, bottom rails, pulley stiles, and other horizontal timber elements. This is why end grain and joints are often first to fail, or why you might find rot in certain elements of a timber window or door but not others.
Rotten timber will spread and breed mould, so it’s essential that you find it and repair or replace the affected areas early. The signs to look out for are:
· Soft or cushy timber: Rotten window sills will be soft to the touch.
· Difficulty opening and closing doors/windows: Rot can cause warping, so this is a clear sign of timber decay in listed buildings.
· Doors and windows are draughty when closed: Draughts and poor heat insulation means air is getting through via gaps in joinery or through rotten wood.
Not all damage is indicative of structural rot, and you may be able to repair it easily. However, patch repairs from non-specialists often fail because they don’t identify the cause of the damage; they just repair the symptom. Traditional timber joinery requires an expert eye to find the root of the issue and, if necessary, provide a like-for-like repair or replacement to correct the problem while being respectful of the regulations around listed or heritage buildings.
Condensation, Ventilation and Moisture Traps around Historic Joinery
Not all moisture issues come from outside the home. Windows are seldom opened causing poor ventilation, and heat builds up indoors thanks to body heat and central heating, which allows condensation to pool around windows.
Where previous joinery issues have been treated with low-quality sealants, hard fillers or non-breathable paints, moisture can also become trapped and go unnoticed for quite some time.
What to Check During a Spring Inspection of Listed Building Joinery
During this time of year, we recommend performing a thorough inspection of the internal and external joinery of your listed building, to identify issues before they become more severe. Below is our spring maintenance checklist to help you:
- Open and close each window and door
- Check for sticking, dragging or distortion
- Inspect cills, lower joints and thresholds
- Look for peeling paint, soft timber and failed putty
- Examine areas around gutters, downpipes and masonry junctions
- Note signs of damp staining internally
- Photograph defects to track change over time
If you notice any issues which need more than standard listed building maintenance, please get in touch to request a specialist site survey. We can advise you on which issues are quick-fixes and which need professional repairs or replacements.
Repair Principles: What Owners Should Avoid
Where possible, attempts should be made to repair historic timber windows before replacements are considered. However, you should take caution with DIY repairs as they can do more harm than good. Be careful of hard modern fillers and non-breathable coatings as these may not be suitable for historic timber windows.
As previously mentioned, cutting back on swollen windows will lead to draughts, but indiscriminately applying sealant over cracks and gaps will only contribute to the problem as this will trap moisture inside the timber and cause rot. Instead, consider seeking professional advice on what repairs are most suitable, or if replacement is your best option. For listed buildings, you may need listed building consent before conducting any work on the joinery, and replacements should be made on a like-for-like basis to preserve the building’s heritage.
Conclusion
Although spring itself doesn’t cause problems in your heritage timber windows and doors, it is the time when preexisting problems reveal themselves. The best thing you can do is keep proper ventilation throughout the year – including in winter – and to conduct a thorough spring maintenance check of all your heritage joinery. By doing this, you can address moisture ingress issues, complete early repairs, and hopefully avoid costly replacements of rotten timber frames.
If you notice signs of water damage and want to know how deep the rot goes or next steps for your property, book in a site survey with us and we can help you address all your heritage joinery questions with our dedicated team of professionals.
