Pack 25 Roofing Felt Lap Vent Stops Loft roof Condensation / Attic Space Ventilation Airflow

I bought these as we had a problem with condensation in the loft of our new house. The en-suite bathroom had been vented directly into the loft (not easy to see as at other end of loft from hatch) and was first noticed when I went up to the loft to get the Christmas decorations down. This coupled with non breathable old style plastic roofing liner meant that I then found puddles of water everywhere and water running down the liner and trusses. After fixing the main cause of the condensation (venting the bathroom outside!!) we then needed to increase the airflow to dry out the loft and stop condensation occurring again. Initially I removed the insulation that was stuffed into and blocking the soffits, however I then had a choice to either try these or put vents into the soffits. These were the much easier (but more expensive) install so I thought they would be worth a try. I placed one in every other truss gap in the loft alternating between as low as I could reach and 3/4 of the way up the roof. I was not expecting great results as the loft was very wet, however two weeks later and it was nearly bone dry. Very impressed with the results and saved me from climbing ladders and drilling holes. Obviously it may not be suitable for all situations, but if you have non breathable liners like myself and getting to the soffits to install vents is awkward it may well be worth a try. Also if you have another root cause of condensation like me, then fix that first! Pros: Seems to provide good airflow Easy to install Does the job required Cons: Expensive for what they are.

Item made out of thin plastic but still fit for purpose. Very easy to fit in the felt overlaps, just slides into place & is held in place with it's plastic clips. You can feel air movement straight away if the wind is in the right direction. Fitted early Jan 2017, so far seems to work very well at completely clearing the condensation. I bought 25x (to fit a 5 bedroom house with a L shape loft) but really only needed to fit 20x to get the loft totally clear of condensation. If need be I'll fit the rest later. I suppose it depends how bad the condensation is to how many you need & how you space them. You can check out these on the manufacturers web site which gives product info & fitting PDF files plus a Manthorpe G630 vent installation video.Very useful info. A recommended purchase if you suffer from condensation &. have a felt roof lining in which you can slide these vents.

Stumbled across these as I was looking for an easy way to dry out my loft when the immersion heater boiled the expansion tank ( Long story). But the loft roof was covered in water droplets dripping down getting everything wet. Read some reviews on Amazon and thought they were worth a try before having to concede to an expensive option. I have a 4 Bed detached house it has a large roof so bought the box of 25. They arrived a day early. For what they are the price is probably a bit expensive but having shopped around these where the cheapest. And definitely cheaper than getting someone in to dry it or safer than putting a dehumidifier up there. They took about an hour to fit having to climb around stored stuff and joists. I found a video on YouTube that was helpful and placed them at various heights across the roof. 1 week later I have checked to see if there is any progress. The weather hasn't been too cold but it's still winter and there hasn't been much of a wind either so I wasn't expecting a great deal of change. But I'm pleasantly surprised. There is definitely progress, a lot of dry areas appearing the vents are definitely making a difference. I've moved a few as they had completely dried the area around them. I'll update this review in another week. Ok so it's been a almost another 2 weeks but I'm really pleased with the outcome. Even though the weather turned colder and wetter the loft is now almost completely dry a very fertile water droplets remain on the felt and I'm confident these will disappear in the coming days. Upgraded to 5 stars. 👍👍👍

Going into Autumn 2019 my loft felt was already starting to get wet so, despite a bit of trepidation about these being too good to be true, once the rain really kicked in over the winter I invested in a box of these and haven’t regretted it for a moment. 25 was more than enough for my mid-terrace inner city property. They were easy to install and although my loft isn’t bone dry at least it no longer feels like an Eden Project bio dome up there when the rain falls (and falls, and falls, and falls...) Perhaps They’re a tad bit overpriced for what they physically are made up of and you could make something similar yourself, but as I’m dismal at DIY I suppose I pay a premium for convenience.

I had no problem with damp in my roof space until I fitted a floor in the loft and also we had a shower pump installed which created a lot of steam in the bathroom. Both these factors then contributed to condensation forming in the loft, I went in to the loft to get the Christmas decorations only to find everything wet, the floor had water on it, the felt was dripping, it was really bad and the wooden rafters were also very wet - not good. I read the reviews on this product and thought for the sake of £62 it was worth a try before calling in a roofing expert. It took me around 15 minutes to install 25 vents - very easy indeed. I inspected my loft one week after installation and now it is completely dry, no damp or condensation whatsoever. Even all the water that had accumulated on the floor has dried up in just 7 days. I have seen comments saying that the vents are expensive for what they are - just some moulded plastic which is true but then who cares? - It's what they do that counts - and they solved my roof problem 100% without having to call in experts and saved me a fortune, I'm sure. I just ordered a second pack as the box of 25 fitted about half of my roof space, so I will finish the job off now with another box - I cant recommend these enough.

Very easy to fit and made a big difference to the ventilation in the loft space. Whilst fitting them I noticed that the still stagnant air in the loft started to move as the vents created a nice through breeze. With fresh air being brought into the loft and the old air able to exit the loft now smells much much fresher and nicer to be in. The damp mould smell has gone. The timbers don't feel as damp any more. I will have to wait a bit longer to see if it solves the condensation issue in the loft... but based on what I've noticed so far it seems to be improving. Really easy to fit, biggest problem I had was moving around the loft space due to all my clutter but the product itself takes just moments to install. I went a bit OTT and fitted 25 in my 2 bed semi which is more than needed but I wanted to be sure it was going to ventilate the loft quickly.

Before buying this product,my loft was so damp,all the felt was soaking wet and was dripping down onto insulation wool and timbers.I bought 4 roof tile vents in addition to these felt flap vents.I bought 25 of these and spread them around the roof. They say to put them in the bottom third of the loft at slightly different heights and you can feel the slight drafts coming through the vents. I put 12 on one side and 13 on the other side and a few days later when it was 0 degrees outside when the condensation would have been at its worst in the loft,the felt throughout the loft was bone dry. Its all about ventilation and that's what does the trick.Cost me just over £50 to put 25 of these up there and its totally cured the problem. Cant recommend this product enough.

I have a slate roof with bitumen type roof liner directly under slate. For some while there had been a smell of damp in attic. I bought these and found they were easy to fit and did seem to give some increase in airflow close to the vent. However after a couple of months there was no improvement in damp smell. I eventually found that there was a leak in valley of roof and the damp originated from a wet valley board. The board was replaced and lead valley liner renewed and now the damp has gone. I have left vents in place but I can't honestly say they helped.