Last updated 9th April, 2020
All you need to know about having loft vents installed including costs of materials, costs of labour and time frames.
In some homes if they do not have enough loft vents (or have no existing loft vents at at all) then installing loft vents will normally alleviate any condensation problems, but of course you should also investigate methods of reducing the total amount of moisture getting into the loft too. There are three main types of loft vents; eaves vents, tile vents and ridge vents.
Loft condensation is the result of excess moisture collecting in the loft, this can be caused by either a lack of loft ventilation, a lack of loft insulation, or a combination of both. If you get condensation in the loft space your roof timbers can become damp and develop wet rot, plus the insulating material in the loft will become wet and useless - both of which are more expensive than simply adding some ventilation in the form of loft vents!
If you have a tradesman working in your loft-space, it makes sense to have them take care of other related jobs at the same time to reduce overall labour costs. Other related jobs could include fitting loft insulation, boarding out the loft, or installing a loft ladder and hatch. You also may as well go ahead and have the roof tiles checked and get any damaged or missing tiles replaced.
In fact some companies which carry out insulation work under the Energy Companies Obligation (ECO) scheme, will often supply and fit loft vents for free to avoid the insulation they are fitting getting damp and not insulating your home properly. However they will normally only fit some simple and cheap circular vents, they will not tackle serious loft condensation problems for free, though they may be able to give advice and provide quotes for the work.
There are 3 types of loft or roof vents to consider, ridge vents, tile vents and eaves/soffit vents. Ridge Vents are placed on the highest point of the roof (the ridge) and they help to allow warm rising air to escape. Tile vents replace tiles mid-roof and are compatible with 90% of roof tiles currently used in the UK. For a typical job you would need two tiles to the front and another two at the rear. Eaves Vents are circular vents which are installed at eaves level in the soffit board and allow an airflow into the loft space, these type of vents are often installed in conjunction with ridge vents for additional ventilation.
Whenever you are working in the loft space it is important to remember that the ceiling is not designed to take your weight. The number on reported disaster with this type of work is falling through the ceiling - which can turn a small inexpensive job, into a major project costing a fortune! Also it is always worth getting professional advice before installing loft vents, as you can over-ventilate the roof space leading to more problems, typically extra ventilation is generally easier to add later, rather than trying to remove ventilation after fitting if the loft space gets too cold in winter.
To install twenty circular/eaves vents in total to the front and rear of a typical semi-detached or terraced house in the UK would cost around £250, installing four roof vent tiles would typically cost £400, whereas installing four ridge vents to a typical property is around £300.
Most roofers charge around £250 per day and tend to work in pairs for safety as well as practical reasons. With the 3 types of loft vents it's recommended to install at least 1 type and more often than not it's better to install 2 types however all 3 at the same time is a bit overkill.
Here are a few average costs for hiring a roofer to install some tile vents on your roof to prevent/reduce condensation build up in your loft:
|4 Ridge Vents only||£300||3-4 hours|
|4 Tile Vents only||£400||4-5 hours|
|20 Eaves Vents only||£250||3-4 hours|
|4 Ridge & 20 Eaves Vents||£500||6-8 hours|
|4 Tile & 20 Eaves Vents||£600||7-9 hours|
|4 Ridge & 4 Tile Vents||£600||6-8 hours|
Individual costs for hiring a roofer to install 4 ridge vents and 20 eaves vents to a 2-storey semi-detached house with easy access - Total Cost: £500