Non return valves are fantastic bits of kit if you know what you are doing with them, how they work, what they are for, where you can and should fit them, how to fit them and are you fitting the right type. Me, I will only use ‘Ratwalls’ they really are the best in my opinion.

Recently i was involved in a rat infestation in Solihull, West Midlands, which had been on going since the customer had had his extension built, not by builders may I add, lets just say it was a family project.. (Everyone in the family had a trade) so they pooled together and got on with the job. As soon as the last brick was laid noises were heard in the loft space. The customer was in complete denial and would not except that something must have not been capped off or blocked off correctly allowing rats to get in.

A CCTV survey was carried out and there we have it.. they’d only gone a built over a inspection chamber, which was now covered in posh marble tiles. In moving the toilet around they had run a new 110mm external poly pipe along the side of the building to a newly installed pre-formed chamber in the garden, what they didn’t do was cap off the original line correctly, rats had found a weak point and breached.

At this point options were to take up the beautiful newly laid marble floor, excavate the concrete, expose the chamber and fit a £12.99 bung in the line.. it would cost hundreds if not a couple of grand to carry out these works. Or the installation of a NRV is undertaken (These should never be used as a permanent solution, but will give much needed relief until a more permanent fix is carried out)

I explained that I would only use a certain type and that is all I would recommend especially with the fact that it would need to be fitted in 110mm Poly and not 100mm Clay. I gave my quote (very competitive might I add) which was promptly dismissed as he said he would order one of a rain forest website and fit it himself. With a grand saving of £34.00 excluding my service charge.

Two weeks later…. my customer incensed with rage calls me, I was wrong, there was nothing wrong with his drains, I didn’t know what i was talking about..! I don’t know my job..!! he was still hearing noises, they were worse than ever, the rats had gnawed at the kicker boards in the kitchen and cause lots of damage. We all make mistakes, we all miss things, we all get things wrong. “I can not apologise enough Sir, i’ll get straight back”

I moved some calls around and promptly re-attended the property apologising as I entered the house. Again I was told that I was wrong, he had spent unnecessary money on buying the ‘ratwall’ and he wanted compensating for the damage done by the rats as I had incorrectly identified to source of the infestation.

Scratching my head whilst being shouted at as i walked around the detached property looking to see if I had missed the obvious my years of experience and gathered knowledge which I had collected from some very experienced PCT’s on my time (one of which could catch his dinner (RIP John L)) once again lead me back to the drains.. I referred back to my recording, was I wrong.. I was sure I wasn’t after reviewing the footage.

I asked the customer if he had fitted the NRV..? yes was the annoyed reply.. so I lifted the chamber lid and there it was in all of its glory.. A cheap, incorrect sized, incorrectly fitted NRV.

The only thing this was any good for was given the entering rat a nice back scratch as it passed under the central flap as the NRV had been fitted backwards and was designed for a 100mm diameter pipe not a 110mm poly pipe. He’d essentially blocked his drain to downstream flowing foul waste while leaving the flap free to open up once a rat pushed agains it. As it was a cheaper unit the central flap there was also a degree of backward swing on the flap so even a fair sized rodent could have pushed on through whilst getting a massage..!!

I then promptly fitted my Ratwall.. and proudly took another picture displaying the difference..

Now you can see why I only fit the best (in my opinion) unless vermin arrive with high octane cutting equipment they ain’t getting through these things. ** Please note that it is important that the information card supplied with the unit is clearly displayed confirming the installation of the NRV in the event that the drain blocks up. Rods or a jetting hose could get stuck on the ratwall when pulling back.**

However, sometimes you just can not help some people. Unless I supplied and fitted the NRV completely free of charge to compensate for the customer buying and incorrectly fitting his own incorrectly sized NRV then he would leave me a bad review. I promptly removed my new shiny Ratwall. Sorry sir, I don’t do threats.

We reached a agreement based on trust (I’m far to trusting for my own good) I fitted my NRV correctly, he paid me for my time and the Ratwall on the understanding that if he had any activity after 7 days I would return his money (7 days would allow for the rat(s) to pass through the NRV and not be able to return if there were any in residence at the time of fitting) This would either be disproven or proven by me providing a food source and Saturn Dust to a area known to be frequented by the rats..

Its been three weeks, no angry phone call, no noises, no activity, and no apology… lets hope he’s polite when I book the appointment to go clean the dust up, free of charge I might add.