Mar 19, 2012 – Still Getting In?

QUESTION:

I have a client with an ongoing problem with roof rats inside their building. We know we have closed up all openings, but somewhere they are still getting in. I am wondering if there may be a pipe from the sewer that is open somewhere in the walls and do you know of a way to locate that without destroying all the walls? We have found two pipes so far that they were coming in on and sealed those. There is no crawl space under the building. Thank you for your help.

ANSWER:

It would probably be useful to take yet another slow walk around this building (a house?) to see if there are any more openings that you may have missed. The inspection needs to be from ground level to the roof and up on the roof itself, as rats are such excellent climbers that going vertically is not terribly challenging to them. Perhaps there are some openings around soffits or vent screens, around and under flashing on the roof, or simply through the roofing materials themselves depending on the kind of roof they have. Some of these new concrete tiles can leave decent sized gaps, as can Spanish tiles, and all the Roof Rat needs is that 1/2 inch wide gap to squeeze on in. Finding all potential entry points is a serious challenge, and overlooking one or two that the rats then find would not be unusual. 

From the anecdotes and stories we read occasionally about rats making their way up from sewers and into toilets, using the pipes as their pathway, this could be another route. This would be something a plumber might have to be called in for, and they do have the tools for snaking a camera into pipes to check on the integrity of those lines. This is done commonly to check for broken pipes under slabs or for outdoor pipes where tree roots may have invaded. Since this building is on a slab I would think that a break in any pipe within the walls that is bad enough for a rat to squeeze through would also be creating some sort of serious water leak at that point, and there might be evidence of this on the walls or ceiling. But, if you suspect it and the customer is willing to pay for it the services of a plumber would be the route to go. It just seems to me, from my blind perspective here, that an overlooked outside entry point would be more likely and less costly to check on. 


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