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Most flood preparation focuses on the front door. Sandbags, flood boards, door skirts — all aimed at the threshold. Meanwhile, water is already coming in through the airbricks, and nobody’s done a thing about them.
The Manthorpe Airbrick Flood Defence is a two-part cover designed specifically for this overlooked entry point. It’s been on the market since 2014 and is made by Manthorpe — a proper UK building products manufacturer making ventilation and roofing products, not a random Amazon listing.
Manthorpe Airbrick Flood Defence Cover
UK-made flood airbrick cover from Manthorpe, with a permanent frame in terracotta, buff, grey, white or blue/black and a bright yellow clip-on deployment cover. Fits standard 9″×3″ airbricks. Screws not included.
Frame colours: terracotta, buff, grey, white and blue/black
How the Manthorpe Airbrick Flood Defence Works
The Manthorpe airbrick flood defence has two parts. First, a frame (available in terracotta, buff, grey, white or blue/black to match your brickwork) that you silicone and screw to your existing airbrick — a one-time installation job. Second, a bright yellow cover that clips onto the frame when a flood warning is issued, sealing the opening completely.
The yellow is deliberate. Flood defence kit fails when people forget to deploy it in the rush of a warning. The yellow cover is visible from ground level at all times — you can see at a glance whether it’s on or off. Once the threat has passed, the cover unclips and stores away. The frame stays in place permanently, and with five colours to choose from, you can pick the one that blends best with your brickwork.
Installation
The Manthorpe airbrick flood defence is not a snap-on product — the frame needs fixing to the wall, which is a one-time job. You’ll need:
- A tube of exterior silicone
- Screws and a drill with masonry bit
- Approximately 15–20 minutes per cover
Note: screws are not included in the box — bring your own. Fitting instructions are included. Once the frame is fixed, deploying the yellow cover in an actual warning takes seconds.
Before ordering, measure your airbricks. The Manthorpe airbrick flood defence is designed for the standard UK 9″×3″ airbrick and works with plastic, clay, or concrete bricks. If you have 9″×6″ double-height airbricks, you’ll need two covers per opening. Measure first.
Does the Manthorpe Airbrick Flood Defence Actually Work?
One Amazon reviewer — whose home flooded via airbricks, losing all ground-floor carpets — ordered one to test the fit, then immediately ordered eleven more. Their 72-year-old husband fitted them without difficulty. It’s the kind of real-world endorsement that means more than a spec sheet.
The product has been available since April 2014. It’s well reviewed, and the critical reviews flag the missing screws (fair point) and one reviewer noted slow fitting — both reasonable observations about a product that requires a modest installation effort.
The Value Calculation
Most UK terraced and semi-detached homes have three or four ground-level airbricks. Fitting a Manthorpe airbrick flood defence to each one is a modest outlay. Against the cost of replacing sodden carpets, flooring, and furniture — the average UK flood insurance claim runs to several thousand pounds — that’s not a difficult calculation.
The Manthorpe airbrick flood defence is the only widely available airbrick flood cover from an established UK manufacturer. That matters when you’re buying something that sits on your wall for years and needs to perform reliably the one time conditions require it.
Manthorpe Airbrick Flood Defence Cover
UK-made flood airbrick cover from Manthorpe, with a permanent frame in terracotta, buff, grey, white or blue/black and a bright yellow clip-on deployment cover. Fits standard 9″×3″ airbricks. Screws not included.
Frame colours: terracotta, buff, grey, white and blue/black
What the Rest of the Team Think
🦆 Keith
I’ve fitted six frames. My house has four airbricks. I found two more on the front elevation that I’m fairly sure are decorative, but I’ve covered them anyway. My wife has drawn a map of where they all are. I consider this thorough.
⭐⭐⭐⭐⭐
🪖 Black Panther
Permanent frame. Rapid-deployment cover. Visual status indicator. Civilian equivalent of closing a bulkhead. The yellow is unconventional but the principle is correct — you confirm closure, you don’t assume it. Carry on.
⭐⭐⭐⭐⭐
🤡 Camping Clown
I’ve got the hydraulically-sealed stainless steel version with the integrated pressure sensor and the app. I could have bought twenty of these for the same money and covered every airbrick on the street. I’m genuinely not sure that would have been worse.
⭐⭐⭐⭐
🐾 Weekend Warrior
Pickle investigated every cover during installation. She tried to remove one. She failed. I take that as an independent stress test. Four frames in an afternoon with a cordless drill. Pickle supervised from a safe distance and gave it a cautious pass.
⭐⭐⭐⭐⭐
🐕 Pickle
“Snorgle!”
(Translation: “I tested one with my teeth. It held. My review is complete.”)
🐔 Chicken Licken
Did you know most UK homes flood through the airbricks before a single drop comes in under the door? I’ve been saying this for years. Nobody fitted covers. Now there’s a product and suddenly everyone’s interested. I’m delighted. I’m not at all bitter about the years of being ignored.
⭐⭐⭐⭐⭐
📋 Clarissa
I have a laminated plan of the house showing all airbrick locations, installation dates, silicone brand used, and next inspection date. The yellow covers are checked on the first Sunday of each month. Janet has done the same.
✅✅✅✅✅
🚩 Surviv’l Gurl
I didn’t know airbricks were a thing until this week and now I’m genuinely horrified that I’ve been leaving holes in my house this whole time 😭 The yellow covers are a vibe though. Did a reel. 4,000 views. Airbrick content is having a moment apparently.
🚩🚩🚩🚩🚩
🌿 Aroura
The home breathes through its airbricks as we breathe through our lungs. In flood time, we close what must be closed, mindfully and with intention. A small act of protection for the space that shelters you. The yellow cover is the colour of awareness. Namaste 🙏
⭐⭐⭐⭐
Pros and Cons
Pros
- The Manthorpe airbrick flood defence seals the entry point most flood kits ignore
- The bright yellow cover shows at a glance whether it’s on
- The frame stays fitted permanently, so putting the cover on takes seconds
- The frame comes in five colours to match your brickwork
- Made by an established UK building products manufacturer
- Fits standard 9″×3″ airbricks in plastic, clay or concrete
Cons
- Screws aren’t included with the Manthorpe airbrick flood defence
- The frame needs drilling and siliconing on, about 15–20 minutes per cover
- Double-height 9″×6″ airbricks need two covers per opening
Frequently Asked Questions
Does this fit all airbricks?
The Manthorpe airbrick flood defence fits the standard UK 9″×3″ airbrick (approximately 215mm × 65mm). If you have 9″×6″ double-height airbricks, you’ll need two covers per opening. Measure before ordering — non-standard sizes may not seal cleanly.
Do I need to remove the frame when there’s no flood risk?
No. The frame stays on permanently. Only the bright yellow cover is removed after a flood warning passes. The frame comes in terracotta, buff, grey, white and blue/black, so you can match it to your brickwork.
How many do I need for a typical UK house?
Most UK terraced and semi-detached homes have three or four ground-level airbricks. Walk the perimeter and count them — include any on side elevations and at the back.
Does fitting the covers affect ventilation?
The permanent frame doesn’t restrict airflow — it’s the yellow cover that seals the opening, and that’s only clipped on during a flood warning. Normal ventilation is unaffected when the yellow cover is stored away.
Is this suitable for flats?
Yes, if you have accessible ground-level airbricks on your property boundary. Communal airbricks in shared areas would require building management agreement.
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