This type of vent may also be referred to as an eaves vent. These vents can be found installed in many modern houses and are typically built into the soffit. The result is continuous 10 – 25 mm ventilation at a low level around the eaves of a property. Our roof ventilation range is entirely British manufactured, as are the majority of our products; proudly supporting British manufacturing and minimising risk in the supply chain and in your project schedules. Roof and eaves ventilation – complete solutions If you’re looking specifically for turbine vents, find out how many turbine vents you need using our guide. Wall vents that provide air to a room with heat-producing appliances (e.g., gas appliances or central heating boilers). It is recommended that one ventilator panel is fitted between each rafter in the lowest underlay lap above the level of the insulation layer in the loft on both sides of the roof (see product brochure fig. 1).

Felt lap vents are designed to increase the amount of ventilation in existing roof spaces. They tend to be fitted retrospectively to properties which have additional loft insulation, with the roof lap vent helping to combat the issue of condensation accumulation. Essentially there are two elements to dealing with condensation; the first is to understand where comes from, and the second is how it is removed from your home. Selecting the amount of airflow, then dividing the roof length by the spacing (in meters) indicted below. This should be clear of insulation (or anything else for that matter) so that air can flow up into the loft space, circulate and then out the other side removing any moisture by cooling warm air down before it hits a cold surface. One issue that can arise is “ice damming”. Many homeowners and professionals who are familiar with these lofts issues know of this problem.Normal air gets warm and rises. It filters through the ceiling, getting warmer as it passes through warm rooms and eventually gets into the loft. The loft is usually colder than the house rooms and as soon as the rising warm air hits a colder surface the vapour immediately turns to water. It is possible for rainwater and condensation to run down the roofing underlay and drip though the opening cut into the underlay. This will usually be apparent on the outside of the vent, or on the underlay. To prevent this, the underlay should be cut and dressed around the opening to divert any rainwater or condensation around the opening in the roof. Also known as an ‘over fascia vent’, fascia ventilation allows air to pass into the roof space between the felt and fascia board.

The Manthorpe Felt Lap Vent is a refurbishment product designed to increase the amount of ventilation into existing roof spaces. At this point (called the eaves) there should be a gap between the underside of the roof and the outside wall. This gap should be about 50 – 75mm wide and will usually have a meshed grill within it stopping insects and birds getting in.We are quite used to seeing condensation in the bathroom, firstly in the form of hot steam as we shower or bathe, but then, as the bathroom cools, the steam condenses on the ceiling, cold water pipes, tiles etc. It is not so obvious in the loft. Usually fitted retrospectively to properties with additional loft insulation recently installed, however the Felt Lap Vent will help to combat the problem of condensation build up in any roof space with a lapped felt/membrane construction. If you are suffering from condensation in your loft it will be a “cold roof”. This is the most common type of roof with a loft or attic.

There are a wide variety of roofing vent types available. Here is a brief overview of the most common. Roof tile vent A cold roof is the traditional roof design. This type of roof has dominated loft spaces for decades and continues today. In the modern-day, they are commonly insulated at ceiling level using fibreglass insulation laid across ceiling joists. So, what is the point of roof ventilation? Well, it’s helping your roof “breathe” and reduce weather from affecting home functions. In this guide, you’ll learn what roof vents are, what the different types of roof vents are and more to help you install the ideal roofing vents on your home. Condensation will tend to be on the high parts of the roof, where as a leak might not be, or the evidence of a leak might be lower down. Condensation will be there on cold days because water condenses when the warm moist air touches a cold surface. Leaks will typically show during or after rain. In cases of severe condensation or for large roofs where the distance between eaves exceeds 10m (30ft), or the roof pitch is steeper than 35o, then it is recommended that an additional row of ventilation panels be fitted into the highest line of roofing felt or underlay lap closest to the ridge on both sides of the roof.Ice damming’ occurs when heat from inside the attic combines with the sun’s heat. It melts the snow and ice on your heated roof, letting the water run to the edge of the roof and begins to refreeze. If you are in any doubt about your own loft, you should seek advice from a builder or roofer. You can find one local to you here. Cold Roof versus Warm Roof Ventilation ridge placed on roof with slit cut into felt to allow warm air out. Images courtesy of roofing ventilation.co.uk Slate roof vent tiles are also ideal for easy installation and the range of designs available. They can blend in nicely with slate tiles. So, if you would like something that suits the slate-style roof, consider these. The lap vent is another easy solution for ventilation problems. Especially in poorly vented areas of the property. Though commonly used on older roofs with bitumen sarking felt (waterproofing layers), they can also be fitted to roof membranes if needed.

Quite often people see some signs of damp in their loft, or water dripping from the underside of the felt or rafters and automatically assume they have a leak. This is most definitely, not always the case. I'm thinking I need to sort this out before I make the attic even colder with the extra insulation. Would felt lap vents like these:An ideal part of this type of ventilation is that little to no maintenance is required. However, if applied with sand and mortar, they need to be replaced with mortar bonds. How you figure this out will depend on the age and type of property. You can do roof vent size calculation yourself or consult with a professional roofing expert. If you decide to work out the vent amount yourself, consider adding a little extra to the overall total. Don’t go over the top though, as this is difficult to alter in future. The panels should be fully inserted with the ribs uppermost and the two retaining tabs locating over the exposed edge of the roofing underlay. Over vent” fascia is another good solution for problematic roofing spaces but does not offer as easy of an installation process. However, the mesh grill design keeps out pests and is ideal for those who desire a hidden solution, unlike soffit vents. We have a full description of the different types of roofs and their insulation in this project, however simply a “cold roof” is one where the insulation in on the loft floor keeps, or is supposed to keep, the warmth in the room below.