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Leaking Conservatory: Causes and How to Fix

28 June 2024
Conservatory extensionConservatory extension


Adding character, brightness and extra space to your home are a few of the reasons why you might have chosen to build a conservatory. That’s why issues like leaking can be so frustrating. Or you may have moved into a house with an older and poorly-fitted conservatory that is now unusable.

Fortunately, there are ways to prevent and repair the issues that cause leaks, and innovative conservatory conversions which keep it water-tight all year around. We put together this guide to help you understand the causes of a conservatory leaking, how to fix them, and your options if it's beyond repair. 

Why is my Conservatory Leaking?

A leaky conservatory isn’t only unpleasant to sit in – it can lead to more serious  issues like structural and water damage and mould, which ruins your paintwork and furnishings, and could be unsafe if it gets into plug sockets or wires. 

There might be a number of reasons why your conservatory is leaking – but whatever the cause, tackling it as soon as you notice it can prevent long term damage. 


Wear and Tear

Conservatory roofs are typically manufactured from glass, polycarbonate or tiles, and held together by a frame made from U-PVC, timber or aluminium. The panels are secured with screws and sealant, or flashing where the conservatory meets the exterior wall. 

Over time, the sealant or flashing can break down causing gaps or cracks that allow water to enter. Timber frames are also susceptible to rotting and warping in the rain which can lead to water seeping in. 


Improper Installation

If the flashing, sealant, roof panels, doors and windows are installed incorrectly, water can seep in. So, it  needs to be fitted accurately and securely to prevent any gaps or damage caused by bad weather. 


Your choice of material can also increase the risk of leaking. For example, a polycarbonate roof may crack if exposed to the sun for a long time, and it expands and contracts based on the weather. If it’s not fitted to adapt to these changes, you might be left with gaps. A glass roof can also leak if it gets damaged or cracked, and may be more prone to condensation.  

Flat roofs are also more likely to leak if they’ve been installed badly, and don’t have adequate guttering.


Blocked gutters 

A blocked gutter can also lead to water leaks in your conservatory. If the water can’t flow, it could leak into your walls or roof and create or worsen existing gaps. 



It may seem like you have a leak, but the culprit could be condensation – made worse by poor insulation or single glazed windows and doors. Condensation happens when warm air meets cold surfaces, and older conservatories tend to get really cold in the winter so there is more chance of water droplets dripping down your walls or roof. Activities like exercising in the conservatory can also make it worse because it releases heat into the cold air. 


Conservatory roofConservatory roof

How to Fix a Leaking Conservatory

The good news is, if you catch the source of the leak early, you could repair it to prevent damage. 

Start by inspecting your walls looking for clues of water damage or dampness. Any area that has been sealed, like your windows and doors, should also be checked for cracks. Don’t forget to investigate the flashing on your conservatory roof, and your gutters for blockages. Take care when using a ladder or ask a roofer to help. 

Once you have identified the problem, it’s time to fix it. Depending on the location and severity of the leak, you might be able to fix it yourself or you might have to call in an expert. 


DIY options 


Fill the gaps 

If you notice cracked sealant around your windows, doors or roof panels, it’s a fairly simple fix. Pick up a sealant from your local DIY store for around £5-£10, making sure that it’s weather resistant. 

Start by removing the old sealant from the affected area. Clean and dry the space, and then place your sealant in a caulking gun. Apply the sealant neatly along the affected area and be sure to fill in any gaps well. Using your finger (wearing gloves), run it across the sealant to smooth it and get rid of any excess. Once that’s done, let it dry. 

Note: It’s best to replace the sealant in warmer weather so it sticks better and dries quickly

Remove blockages 

If the leak is caused by a blocked gutter, you will need to clear it. 

Safely position a ladder next to the blockage, and then manually remove the debris using your hands or a tool. It will likely be leaves, stones or twigs, but wear gloves to be on the safe side. Flush some water down the gutter to check if the blockage is fully removed and that the water flows. 

Open doors and windows  

Keep your conservatory well ventilated to prevent condensation. 

You can do this by keeping your windows and doors open if it's not raining, by using a dehumidifier which sucks moisture from the air, or a fan to keep the temperature cool. 

Good insulation and double-glazing can also prevent condensation. Eurocell’s Equinox tiled roof solution is designed with a gap between the aluminium rafters and timber deck to improve ventilation and reduce condensation. 

Conservatory with doors openConservatory with doors open

Call in the experts


Repair the flashing 

While you might be able to replace flashing yourself, it’s best to enlist the help of an expert who will make sure it's watertight and secure. It might not seem like it, but it is a technical repair that requires accuracy. 

A professional tradesperson will need to safely access the area. Once that’s done, the expert will measure and cut the flashing to size, remove the existing one, dig out any excess mortar, and then finally, shape and install it.  

Replace roof panels 

If a roof panel is cracked or damaged, an expert will have to replace it. He or she might need a ladder or scaffolding to access it from the outside. 

The screws securing the panels and any sealant will need to be removed first. Next, the new roof panel should be positioned with precision and screwed in, following the manufacturer's guidelines. The sealant will then add extra weather protection. 

Replacing the roof  

If the roof damage is substantial, you might need to replace the entire roof. 

Opt for a tiled roof which is weather resistant and watertight on day one of installation. It can be installed in just two days and insulates your room so that its energy efficient and inviting, no matter the weather. If you opt for one with glazed panels, like our Equinox Vega it will still let in plenty of light and can be fitted onto all types of conservatories – old or new, provided the structure is sound and capable of withstanding the roof.


How to Prevent your Conservatory Leaking

Like the saying goes, prevention is better than cure, and this certainly applies to a leaking conservatory. 

Choose a conservatory and materials that are high quality and modern, because they tend to eliminate issues facing older conservatories like condensation, draughts or leaks. Opt for double-glazed doors and windows for added security, improved energy efficiency and no condensation. 

Make sure it’s built by a professional, so that all the components are installed accurately and are watertight. 

Set aside time to inspect your conservatory for any gaps or cracks. Look in high risk areas like roof panels, flashing, windows, doors and frames and take action straight away to prevent it from getting worse. 

Trim any bushes or trees around your conservatory guttering to prevent blockages. If winter is coming, get the cause of the leak sorted as soon as possible because it will be harder to repair in the rain. 


What to do if Leaking Conservatory is Beyond Repair?

If you think your conservatory is beyond repair, but don’t want an extension, there’s a middle ground. Modern solutions, like a Eurocell conservatory conversion, can replace your old conservatory in as little as two weeks with minimal disruption and mess. If you’re wanting to change it up more than a replacement, consider a completely new conservatory.

The innovative build starts by recycling your old conservatory to replace it with a strong house extension. It can be built onto your existing conservatory base, so there is no need to dig messy foundations, and the panels are built off site to minimise disruption. It’s also fully insulated to prevent condensation and improve energy efficiency. 

The best part is, modern conservatory replacements reduce issues like leaks and draughts, and turns your conservatory into a space you can love all year round.

Find out more about conservatory conversions.


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