Want to protect your home from damp?
Imagine it’s a night in early December. It’s a cold, wet Winter night.
It’s time to pull out the old Christmas decorations from a cardboard box in a dark corner of your loft.
As you reach out and drag the box towards you, the cardboard feels different. When you pull it further into the light, you realise it’s wet.
You look up and see little beads of water on the inside of the roof.
A wave of panic washes over you. What else is getting wet in here?
Family photo albums? Antique furniture? Clothes you planned to sell to make some extra cash?
The fear of damp sets in. And that's a logical fear.
Damp can cause all sorts of problems from rot to black spot mould.
Damp can damage your home and your health. If you have respiratory problems, exposure to damp can be a big health risk.
But take a deep breath...
Condensation and damp can be treated fairly easily. You might even be able prevent the problems before they develop.
Roof Tile Vents - The Ultimate Guide puts every potential solution in one neat place. And you'll find out how to choose the best one for you and your home.
What Causes Condensation and Damp?
A roof used to be installed over a breathable membrane. As the name suggests, a breathable membrane is designed to let your home “breathe”.
In recent years, the effectiveness of these membranes has been questioned. New builds require roof tile ventilation to pass building regulations and owners of older homes are installing roof tile vents to improve ventilation.
The addition of extra loft insulation can also reduce the effectiveness of eaves vents - sometimes blocking them completely.
The Problem with Old Homes
So what actually happens when you don’t have enough roof ventilation?
Warm air rises and meets the inside surface of the roof. The temperature difference causes the moisture to condense forming condensation.
Heat and moisture is produced from many activities. Cooking, drying your clothes and taking hot baths or showers are the 3 main sources.
You might be unaware of condensation in the loft until one Winter’s night when it’s time to get the Christmas decorations down.
Then panic sets in that it’s too late to stop the damp that’s started.
But don’t worry - it’s not too late. Damp in its early stages is relatively easy to treat.
There are 2 main solutions to the problem of loft condensation.
- Waterproof insulation membrane
- Roof tile vents
Waterproof Insulation Membrane
A waterproof insulation membrane is a thin layer you place under the insulation between your loft and your upstairs rooms.
It is designed to prevent warm moist air from moving up from the house into the roof space.
They can be useful but there are still points like the edges where air can still get through.
There are many different types of roof vent on the market. Each option has it’s good and bad points. I’ll quickly go through them here to save you some time.
Soffit vents are installed under the eaves of a roof. They let fresh air up into the loft to improve air circulation. This prevents loft air from going stale. When combined with roof tile vents they work efficiently to draw air in through the soffit vents and exhaust warmer air through the roof tile vents.
Pros - Easy to install. Unlikely to be blocked by snow.
Cons - Designed mainly for air intake so will need different roof vents to exhaust.
Fascia vents are installed over the fascia boards to provide low level ventilation. They could offer a better alternative to soffit vents, because soffit vents can accumulate dust and debris. This can require regular maintenance and cleaning work.
Pros - Fascia vents are unseen, unlike soffit vents. Mesh keeps out bugs and insects.
Cons - Not an easy DIY option. Can leave little room for guttering installation.
A cowl vent is a hooded roof tile vent designed to replace existing roof tiles. They can also be connected to a bathroom extractor fan using a flexible pipe adaptor.
Pros - Easy to install. Prevents draughts and wind-driven rain. Prevents entry of bugs and insects.
Cons - Doesn’t look great, breaks the appearance of the roof.
Lap vents slip in between an overlap in the horizontal undersarking inside the loft, providing an air path for the wind blowing up the face of the roof outside.
Pros - Simple, easy and effective. You can fit them from inside the roof so you don’t have to worry about external access or getting up on the ladder.
Cons - You need a safe floor to work on because you are fitting from inside the loft. Lap vents might not provide as much ventilation as roof tile vents.
Dry Ridge Vent
Dry ridge vents can be used on the apex of a roof to provide high level ventilation and exhaust moisture. Dry ridge vents aren’t really designed to be used as vents alone. They are more of an exit point than a source of ventilation. They can be used in combination with other forms of lower level ventilation such as eaves vents or soffit vents, fascia vents, or roof tile vents.
Pros - If positioned on the apex of the roof with the felt or undersarking suitably cut immediately beneath, they do provide excellent natural air movement.
Cons - If you live in an exposed location and have large soffit vents as well, too many ridge tile vents have been known to cause too much ventilation on very windy days, possibly blowing the insulation about near the edges.
Inline Slate Vent
The Inline slate vent is designed to replace existing roof slates. Slates come in 2 standard sizes - 600 x 300mm (24 x 12 inch) and 500 x 250 mm (20 x 10 inch).
You can get them in plastic and sometimes real slate. They have a grille and underbase that allow air to flow through the vent and out of the roof. Most slate vents have the option of a pipe adaptor fitting to create a connection for bathroom extractor fans and soil vent pipes.
Pros - Easy to fit. Look better than cowl vents.
Cons - Must be fitted from the outside.
Roof Tile Vents
Roof tile vents are by far the easiest professional solution to roof ventilation problems. They are easy to fit either during the process of installing a new roof, or retrofitting to older existing roofs. One vent replaces one tile.
There are roof tile vents designed to fit most tile profiles on the market. You can buy them in the same colour as your existing roof tiles to maintain the appearance of your roof. Most roof tile vents have the option of a pipe adaptor fitting to create a connection for bathroom extractor fans and soil vent pipes.
Pros - Easy to fit. Look good. Available for most types of roof tile.
Cons - Must be fitted from the outside.
Which Roof Tile Vent Do I Need?
There are 5 ways you can find out which roof tile vent you need.
- Find a spare tile and check the back for brand name and model.
- Ask a professional roofer.
- Use Google images to look for similar roof tiles.
- Visit tile manufacturer websites such as Marley, Redland and Sandtoft.
- Send a photo via the Contact Us page at https://beddoesproducts.com/
Here’s a table of popular roof tiles with their dimensions.
Let's use the example of the Marley Ludlow Major roof tile.
Find the Ludlow Major tile on the Marley website here: Marley Ludlow Major
Let's say you decide using the photos that you have the 'Dark Red' version.
Now go to the Beddoes Products website for the Inline Marley Ludlow Major Vent Tile here: Beddoes Products Inline Marley Ludlow Major Vent Tile and select the 'Red - sanded' option.
What Colour Should I Choose?
Roof tile vents come in 5 basic colours:
Most manufacturers produce tile vents in smooth plastic in these colours.
Some roof tiles are different. They might be a mixture of 2 colours or old and weathered, causing the colour to change.
In these situations, the basic colours can stick out among your roof tiles like a sore thumb.
So how do you find a colour to keep your roof looking the same?
At Beddoes Products, we manufacture everything in-house.
Our products come in any colour in smooth or granular finishes.
We can also colour match to existing tiles. Just send us a photo.
Check your tile manufacturers’ website and search for your tile.
Some brands use different names for similar colours to their competitors. For example, Marley Old English Dark Red is a close match to Redland Farmhouse Red.
Ask for a colour match or leave a note with your order.
How Many Roof Tile Vents Do I Need?
Finding the right number of roof tile vents can be more of an art than a science. It depends on your house’s age, property type and location.
It would be useful to ask for advice from a professional roofing expert, but you might want to make your own estimate.
Consider adding slightly more ventilation than is needed to allow for extreme weather conditions, while keeping costs as low as possible. Try to find a balance.
1. Find total airflow required. Discover the length of the ridge of the roof in mm.
Length (mm) x continuous airflow required.
Example: 10m long roof requiring 5mm continuous airflow.
10 metres = 10,000mm long roof followed.
Then 10,000mm x 5mm = 50,000mm2 airflow required.
2. Work out the number of vents required, asking how many vents it would take to provide the same amount of airflow.
Total airflow (provided by first calculation) ÷ airflow per vent.
Example: For the Beddoes Products Plain Tile Vent with an airflow of 7,500mm2
50,000mm2 ÷ 7,500mm2 = 6.67 vents (which would require 7 vents).
3. Calculate the centres of the vents, checking how far apart they need to be.
Length of roof ÷ number of vents
Following the above example: 10,000mm long roof ÷ 7 = Centres of 1,429mm.
Instead of putting 7 on one side of the roof, you would stagger them on opposite sides to get the best airflow.
Staggering would mean placing 4 vents on one side at 3 metre centres. Then placing the remaining 3 vents on the opposite side at 3 metre centres, but in between the 4 on the other side.
Think of it like this. If you were to draw a line between the vents on both sides, it would look like a zigzag.
Where Can You Buy Roof Tile Vents?
Builders Merchants and DIY Stores
Buying in-store can be good if you’re lucky. You can see the product close-up to check suitability and quality.
The problem is most stores only have a small range of products with limited stock. Colour choices will also be limited.
eBay has more product options than most builders merchants. If you search regularly, you might pick up some cheap deals from someone selling old stock.
Online roof tile vent stores have the biggest range of products with the best colour flexibility.
You could go directly to the big roofing stores. However, it might be better to Google search specific terms like “Marley Ludlow Major Vent Tile” to find exactly what you’re looking for.
I prefer this method because it means less pages to click through trying to find the right product category on bigger roofing websites.
In this guide, you've learnt how to decide whether you need roof ventilation, how to choose the best roof vent for your home, how to select the right roof tile vent, how to find your colour and where to buy from.
Now it's time to apply everything.
Browse the Beddoes Products Roof Tile Vents Collection.
Need help? Head over to our Contact page.