Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks

On Friday, 6 January 2017 09:46:02 UTC, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks

What you need is drain rods poked in from the nearest ispection chamber.

On 06/01/17 11:50, harry wrote:
On Friday, 6 January 2017 09:46:02 UTC, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks

What you need is drain rods poked in from the nearest ispection chamber.

What inspection chamber would that be harry?

"some *disconnected* clay/plastic pipe-work"...

On 06/01/2017 09:46, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week).But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks


No experience, but I had a look at the Wikipedia article. The photo of
the output looks fairly easy to understand.

What type of soil do you have?

On 2017-01-06 09:51, The Natural Philosopher wrote:
On 06/01/17 11:50, harry wrote:
On Friday, 6 January 2017 09:46:02 UTC, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks

What you need is drain rods poked in from the nearest ispection chamber.

What inspection chamber would that be harry?

"some *disconnected* clay/plastic pipe-work"...


Yes, exactly!

On 2017-01-06 10:05, GB wrote:
On 06/01/2017 09:46, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week).But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks


No experience, but I had a look at the Wikipedia article. The photo of
the output looks fairly easy to understand.

What type of soil do you have?



Gravel and clay.

I note that the resolution is affected by how wet the soil is, but I
think I understand (just) enough to be aware of the affect of the
frequency settings (higher = shallower, lower = deeper).

On 06/01/2017 10:11, WeeBob wrote:
On 2017-01-06 10:05, GB wrote:
On 06/01/2017 09:46, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week).But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks


No experience, but I had a look at the Wikipedia article. The photo of
the output looks fairly easy to understand.

What type of soil do you have?



Gravel and clay.

I note that the resolution is affected by how wet the soil is, but I
think I understand (just) enough to be aware of the affect of the
frequency settings (higher = shallower, lower = deeper).

And, no doubt, you read "In moist and/or clay-laden soils and materials
with high electrical conductivity, penetration may be as little as a few
centimetres."

On Fri, 6 Jan 2017 09:46:06 +0000, WeeBob wrote:

Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Before you splash out a couple of hundred quid on equipment hire and
several hours on a steep learning curve, you could always have a go at
this http://www.groundwateruk.org/Does_divining_work.aspx

All you've got to lose is a couple of bent coathangers and the respect
of your friends and family[1]

Nick
[1]And if successful gain huge respect from friends, family,
neighbours, local press etc etc.

On Fri, 6 Jan 2017 09:46:06 +0000, WeeBob wrote:

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

I've used a couple for a short time, simple they are not.

The first thing is that the specifications are about as accurate as an
85p Chinese watch. "Up to xx ft range" means you might get half that
if searching for a 1ft by 2ft lump of depleted Uranium buried in dry
sand. In normal UK soil anything from a few inches to a very few feet
is the most you will manage.

Secondly the image produced requires a lot of interpretation, you are
often trying to pick up small indistinct patterns in noise. If the
pipes are empty they may show up well, if clay and filled with similar
material to their surroundings they won't show at all or very
indistinctly.

Thirdly, GPR comes in varying frequencies - lower (300MHz) give
better penetration but poor resolution. These are typically used for
archaeology. Higher frequencies (1500MHz) give better resolution but
much worse penetration, about 500mm in good conditions. 900MHz is
often used for pipe detection and has a range of about 1m.

Depending upon how large an area you want to survey you might find it
more cost effective to hire the device plus an experienced operator.

Nick Odell wrote:

All you've got to lose is

.... a lot of wasted effort digging up the wrong area of concrete?

On 2017-01-06 15:32, Peter Parry wrote:
On Fri, 6 Jan 2017 09:46:06 +0000, WeeBob wrote:

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

I've used a couple for a short time, simple they are not.

Thanks for your input.

May I ask, what do you define as a short time?

With a week's rental, I figure I could spend the first couple of days on
known-knowns, and gradually expand over the week.

snip
Depending upon how large an area you want to survey you might find it
more cost effective to hire the device plus an experienced operator.

Any idea what kind of costs this would be? I'm stuck in
"phone-for-quote" land for these services and they all seem geared
towards large projects and I'm interested in a patio.

WeeBob wrote:
On 2017-01-06 15:32, Peter Parry wrote:
On Fri, 6 Jan 2017 09:46:06 +0000, WeeBob wrote:

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

I've used a couple for a short time, simple they are not.

Thanks for your input.

May I ask, what do you define as a short time?

With a week's rental, I figure I could spend the first couple of days on
known-knowns, and gradually expand over the week.

snip
Depending upon how large an area you want to survey you might find it
more cost effective to hire the device plus an experienced operator.

Any idea what kind of costs this would be? I'm stuck in
"phone-for-quote" land for these services and they all seem geared
towards large projects and I'm interested in a patio.



Just out of interest, if these drains are disconnected, why do you want to
find them?

Tim

--
Please don't feed the trolls

On Sat, 7 Jan 2017 13:37:33 +0000, WeeBob wrote:

On 2017-01-06 15:32, Peter Parry wrote:
On Fri, 6 Jan 2017 09:46:06 +0000, WeeBob wrote:

I've used a couple for a short time, simple they are not.

Thanks for your input.

May I ask, what do you define as a short time?

About 2 days a week spread over a month.(The man who really understood
it could only be on site 3 days a week so I played with it when he
wasn't there). We were looking for some 1 inch lead water pipe about
6ft underground and a brick lined chamber about 4ft square with a cast
Iron roof buried about 4ft deep in a field. The chamber I could find
easily, the pipes I never saw despite the normal operator pointing at
a tiny wiggle amongst 3,000 other wiggles and proclaiming they stood
out like a sore thumb. (He was right - they were where he said).

With a week's rental, I figure I could spend the first couple of days on
known-knowns, and gradually expand over the week.

snip
Depending upon how large an area you want to survey you might find it
more cost effective to hire the device plus an experienced operator.

Any idea what kind of costs this would be? I'm stuck in
"phone-for-quote" land for these services and they all seem geared
towards large projects and I'm interested in a patio.

No idea I'm afraid. It was a year ago, the machine and operator were
not paid for by us and it isn't something I've needed to use before or
since.

WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing
that with a few days practise, on a known area that I could get some
useful experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks

If these are unused drains that you want to get to, it would probably be
cheaper to dig up the patio and lay new ones from scratch. Rainwater can go
into a soakaway, sewage can connect to any available sewage pipe and a
plastic manhole installed at the junction

On 06/01/2017 10:08, WeeBob wrote:
On 2017-01-06 09:51, The Natural Philosopher wrote:
On 06/01/17 11:50, harry wrote:
On Friday, 6 January 2017 09:46:02 UTC, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing
that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks

What you need is drain rods poked in from the nearest ispection chamber.

What inspection chamber would that be harry?

"some *disconnected* clay/plastic pipe-work"...


Yes, exactly!

I'm not sure what you're getting at without a clearer picture and not
having to make presumptions.

Most disused pipes should be scrapped from being of an unknown
provenance. Best to start from scratch.

On 07/01/17 20:42, Fredxxx wrote:
On 06/01/2017 10:08, WeeBob wrote:
On 2017-01-06 09:51, The Natural Philosopher wrote:
On 06/01/17 11:50, harry wrote:
On Friday, 6 January 2017 09:46:02 UTC, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing
that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks

What you need is drain rods poked in from the nearest ispection
chamber.

What inspection chamber would that be harry?

"some *disconnected* clay/plastic pipe-work"...


Yes, exactly!

I'm not sure what you're getting at without a clearer picture and not
having to make presumptions.

Most disused pipes should be scrapped from being of an unknown
provenance. Best to start from scratch.
He said he was looking for them, not that he wanted to reusee them

On 2017-01-07 14:11, Tim+ wrote:
WeeBob wrote:
On 2017-01-06 15:32, Peter Parry wrote:
On Fri, 6 Jan 2017 09:46:06 +0000, WeeBob wrote:

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

I've used a couple for a short time, simple they are not.

Thanks for your input.

May I ask, what do you define as a short time?

With a week's rental, I figure I could spend the first couple of days on
known-knowns, and gradually expand over the week.

snip
Depending upon how large an area you want to survey you might find it
more cost effective to hire the device plus an experienced operator.

Any idea what kind of costs this would be? I'm stuck in
"phone-for-quote" land for these services and they all seem geared
towards large projects and I'm interested in a patio.



Just out of interest, if these drains are disconnected, why do you want to
find them?

Tim



Well... thanks for being interested Tim, this may be too much detail,
but here goes:

We have had an on-going problem with rats getting into our roof
structure, and I'm trying to eliminate any possible source of ingress.

We've been through several rounds of bait-and-kill, and have a blimey
load of surveillance (cctv), traps and poison, in the roof (think
"Hunger Games"). Activity dropped to zero about five weeks ago, but a
couple of days ago I noticed we had a new visitor.

Being aware of the need to eliminate all access points, the roof itself
has been inspected (several times) and various potential access points
closed/filled. I've had all the existing drains surveyed, mapped and
proofed where required. There are (now) no climbing plants on the walls etc.

The local pest control guy (who I rate) has inspected the property
several times and we're both baffled about how they're getting in.

The house is a big(ish) bungalow in a semi-rural environment. I
contacted the local council and got copies of all the relevant planning
permissions and it turned out that an extension was added in 1963 and it
is this part that included the flue that you and others kindly
identified in the "Chimney Pot Identification" thread.

After talking with neighbours, it was suggested that the extension was
originally used for commercial food preparation/cooking.

The conundrum is that there is no clear route to the current drainage
from the extension. (The two down pipes in the Chimney thread simply
evacuate onto a gravel bed).

In addition to the extension, in 1963 an adjacent plot was used by the
same developer to construct another bungalow.

Now, my suspicion is that the developer connected the extension drainage
to the adjacent bungalow (it may have been easier).

Subsequently, a later developer (~1980s and for which there is no
planning permission), capped off one of the 4" pipes in the existing
drainage system. We found this during our initial drainage survey, and
it looks like a bodge-job. It allowed access into the floor void and the
cavity wall from the mains drainage network. So we capped this properly
about 18 months ago.

But clearly, it didn't fix the problem.

Maybe 1980s developer did the same/similar thing for the drainage in the
extension, and that's my current line of inquiry.

i.e. drains in extension connected to neighbours drains, subsequently
capped in a manner which allowed access to the extension cavity wall or
even the floor void. (The floor area in the extension is now a mix of
concrete and suspended - but concrete where the drains may have been).

And so my desire to understand what may be going on under the house. I
figure that with a week's worth of rental, I can use GPR internally and
externally to build a map of what is under the extension.

Naturally, of course, I've had discussions with my neighbour about their
drainage, but short of me paying to have their drains surveyed (and/or
scaring a little old lady about having rats in their drains), some
non-destructive GPR strikes me as the best course of action.

A long story, and not finished yet. There is still digging yet to do!

Regards

WeeBob

On 2017-01-08 10:23, jim wrote:
jim k Wrote in message:
The Natural Philosopher Wrote in message:
On 07/01/17 20:42, Fredxxx wrote:
On 06/01/2017 10:08, WeeBob wrote:
On 2017-01-06 09:51, The Natural Philosopher wrote:
On 06/01/17 11:50, harry wrote:
On Friday, 6 January 2017 09:46:02 UTC, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing
that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks

What you need is drain rods poked in from the nearest ispection
chamber.

What inspection chamber would that be harry?

"some *disconnected* clay/plastic pipe-work"...


Yes, exactly!

I'm not sure what you're getting at without a clearer picture and not
having to make presumptions.

Most disused pipes should be scrapped from being of an unknown
provenance. Best to start from scratch.
He said he was looking for them, not that he wanted to reusee them



Contemplating blowing 2-300 quid hiring kit room find them would
suggest there's at least a repurpose afoot...

Room = to.

Grrr. :-)


Rats!

(See my reply to Tim+ @10:58)

The Natural Philosopher Wrote in message:
On 07/01/17 20:42, Fredxxx wrote:
On 06/01/2017 10:08, WeeBob wrote:
On 2017-01-06 09:51, The Natural Philosopher wrote:
On 06/01/17 11:50, harry wrote:
On Friday, 6 January 2017 09:46:02 UTC, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing
that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks

What you need is drain rods poked in from the nearest ispection
chamber.

What inspection chamber would that be harry?

"some *disconnected* clay/plastic pipe-work"...


Yes, exactly!

I'm not sure what you're getting at without a clearer picture and not
having to make presumptions.

Most disused pipes should be scrapped from being of an unknown
provenance. Best to start from scratch.
He said he was looking for them, not that he wanted to reusee them



Contemplating blowing 2-300 quid hiring kit room find them would
suggest there's at least a repurpose afoot...
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

jim k Wrote in message:
The Natural Philosopher Wrote in message:
On 07/01/17 20:42, Fredxxx wrote:
On 06/01/2017 10:08, WeeBob wrote:
On 2017-01-06 09:51, The Natural Philosopher wrote:
On 06/01/17 11:50, harry wrote:
On Friday, 6 January 2017 09:46:02 UTC, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing
that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks

What you need is drain rods poked in from the nearest ispection
chamber.

What inspection chamber would that be harry?

"some *disconnected* clay/plastic pipe-work"...


Yes, exactly!

I'm not sure what you're getting at without a clearer picture and not
having to make presumptions.

Most disused pipes should be scrapped from being of an unknown
provenance. Best to start from scratch.
He said he was looking for them, not that he wanted to reusee them



Contemplating blowing 2-300 quid hiring kit room find them would
suggest there's at least a repurpose afoot...

Room = to.

Grrr. :-)
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

WeeBob Wrote in message:
On 2017-01-08 10:23, jim wrote:
jim k Wrote in message:
The Natural Philosopher Wrote in message:
On 07/01/17 20:42, Fredxxx wrote:
On 06/01/2017 10:08, WeeBob wrote:
On 2017-01-06 09:51, The Natural Philosopher wrote:
On 06/01/17 11:50, harry wrote:
On Friday, 6 January 2017 09:46:02 UTC, WeeBob wrote:
Good morning.

I'm looking for some disconnected clay/plastic pipe-work under an
internal concrete base and/or externally paved patio and I see that
Ground Penetrating Radar (GPR) units are available for hire at an
affordable rate (£200-300/week). But I also see that the data analysis
may be the hard part.

Has anyone here used them? Would they be useful at a DIY level?

I've got an IT background, with some 3d modelling, and I'm guessing
that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

I'd be interested in anyone else's experience.

Thanks

What you need is drain rods poked in from the nearest ispection
chamber.

What inspection chamber would that be harry?

"some *disconnected* clay/plastic pipe-work"...


Yes, exactly!

I'm not sure what you're getting at without a clearer picture and not
having to make presumptions.

Most disused pipes should be scrapped from being of an unknown
provenance. Best to start from scratch.
He said he was looking for them, not that he wanted to reusee them



Contemplating blowing 2-300 quid hiring kit room find them would
suggest there's at least a repurpose afoot...

Room = to.

Grrr. :-)


Rats!

(See my reply to Tim+ @10:58)


Ahgotcha! (ideally)
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

WeeBob wrote:

Well... thanks for being interested Tim, this may be too much detail,
but here goes:

We have had an on-going problem with rats getting into our roof
structure, and I'm trying to eliminate any possible source of ingress.

We've been through several rounds of bait-and-kill, and have a blimey
load of surveillance (cctv), traps and poison, in the roof (think
"Hunger Games"). Activity dropped to zero about five weeks ago, but a
couple of days ago I noticed we had a new visitor.

Being aware of the need to eliminate all access points, the roof
itself has been inspected (several times) and various potential access
points
closed/filled. I've had all the existing drains surveyed, mapped and
proofed where required. There are (now) no climbing plants on the
walls etc.
The local pest control guy (who I rate) has inspected the property
several times and we're both baffled about how they're getting in.

The house is a big(ish) bungalow in a semi-rural environment. I
contacted the local council and got copies of all the relevant
planning permissions and it turned out that an extension was added in
1963 and it is this part that included the flue that you and others kindly
identified in the "Chimney Pot Identification" thread.

After talking with neighbours, it was suggested that the extension was
originally used for commercial food preparation/cooking.

The conundrum is that there is no clear route to the current drainage
from the extension. (The two down pipes in the Chimney thread simply
evacuate onto a gravel bed).

In addition to the extension, in 1963 an adjacent plot was used by the
same developer to construct another bungalow.

Now, my suspicion is that the developer connected the extension
drainage to the adjacent bungalow (it may have been easier).

Subsequently, a later developer (~1980s and for which there is no
planning permission), capped off one of the 4" pipes in the existing
drainage system. We found this during our initial drainage survey, and
it looks like a bodge-job. It allowed access into the floor void and
the cavity wall from the mains drainage network. So we capped this
properly about 18 months ago.

But clearly, it didn't fix the problem.

Maybe 1980s developer did the same/similar thing for the drainage in
the extension, and that's my current line of inquiry.

i.e. drains in extension connected to neighbours drains, subsequently
capped in a manner which allowed access to the extension cavity wall
or even the floor void. (The floor area in the extension is now a mix
of concrete and suspended - but concrete where the drains may have
been).
And so my desire to understand what may be going on under the house. I
figure that with a week's worth of rental, I can use GPR internally
and externally to build a map of what is under the extension.

Naturally, of course, I've had discussions with my neighbour about
their drainage, but short of me paying to have their drains surveyed
(and/or scaring a little old lady about having rats in their drains),
some non-destructive GPR strikes me as the best course of action.

A long story, and not finished yet. There is still digging yet to do!

Regards

WeeBob

It's unlikely that they are getting in through any drains, so i wouldn't
waste any more money following this particular dead end, the drains don't go
anywhere near the roof, if anything, they could terminate under the
suspended part of the floor and this area would be rat heaven. How are they
getting from there to the loft? - there's only one way and that's via the
cavity, which is probably uninsulated given the age of it. Get it filled
with fibre insulation and the rats will go away, they don't like it. There's
grants available and it would probably cost you less than hiring a piece of
equipment that doesn't work.

On Sun, 8 Jan 2017 14:36:32 -0000, "Phil L"
wrote:

WeeBob wrote:

Well... thanks for being interested Tim, this may be too much detail,
but here goes:

We have had an on-going problem with rats getting into our roof
structure, and I'm trying to eliminate any possible source of ingress.

We've been through several rounds of bait-and-kill, and have a blimey
load of surveillance (cctv), traps and poison, in the roof (think
"Hunger Games"). Activity dropped to zero about five weeks ago, but a
couple of days ago I noticed we had a new visitor.

Being aware of the need to eliminate all access points, the roof
itself has been inspected (several times) and various potential access
points
closed/filled. I've had all the existing drains surveyed, mapped and
proofed where required. There are (now) no climbing plants on the
walls etc.
The local pest control guy (who I rate) has inspected the property
several times and we're both baffled about how they're getting in.

The house is a big(ish) bungalow in a semi-rural environment. I
contacted the local council and got copies of all the relevant
planning permissions and it turned out that an extension was added in
1963 and it is this part that included the flue that you and others kindly
identified in the "Chimney Pot Identification" thread.

After talking with neighbours, it was suggested that the extension was
originally used for commercial food preparation/cooking.

The conundrum is that there is no clear route to the current drainage
from the extension. (The two down pipes in the Chimney thread simply
evacuate onto a gravel bed).

In addition to the extension, in 1963 an adjacent plot was used by the
same developer to construct another bungalow.

Now, my suspicion is that the developer connected the extension
drainage to the adjacent bungalow (it may have been easier).

Subsequently, a later developer (~1980s and for which there is no
planning permission), capped off one of the 4" pipes in the existing
drainage system. We found this during our initial drainage survey, and
it looks like a bodge-job. It allowed access into the floor void and
the cavity wall from the mains drainage network. So we capped this
properly about 18 months ago.

But clearly, it didn't fix the problem.

Maybe 1980s developer did the same/similar thing for the drainage in
the extension, and that's my current line of inquiry.

i.e. drains in extension connected to neighbours drains, subsequently
capped in a manner which allowed access to the extension cavity wall
or even the floor void. (The floor area in the extension is now a mix
of concrete and suspended - but concrete where the drains may have
been).
And so my desire to understand what may be going on under the house. I
figure that with a week's worth of rental, I can use GPR internally
and externally to build a map of what is under the extension.

Naturally, of course, I've had discussions with my neighbour about
their drainage, but short of me paying to have their drains surveyed
(and/or scaring a little old lady about having rats in their drains),
some non-destructive GPR strikes me as the best course of action.

A long story, and not finished yet. There is still digging yet to do!

Regards

WeeBob

It's unlikely that they are getting in through any drains, so i wouldn't
waste any more money following this particular dead end, the drains don't go
anywhere near the roof, if anything, they could terminate under the
suspended part of the floor and this area would be rat heaven. How are they
getting from there to the loft? - there's only one way and that's via the
cavity, which is probably uninsulated given the age of it. Get it filled
with fibre insulation and the rats will go away, they don't like it. There's
grants available and it would probably cost you less than hiring a piece of
equipment that doesn't work.

I've no idea how they are getting to the roof but don't discount the
possibiity of them starting their journey through disused drains.

The organisation I work for used to own a repurposed main post office
building. During the early 20thC latrines for the posties were
installed in the undercroft and these were all but forgotten about in
modern times..

....until rats started getting into the building. They had crawled
their way down the disused waste pipes from outside. How they got into
the building from the undercroft I have no idea (cf with the OP's
roof) but pouring cement into each and every WC and basin stopped the
problem.

Nick

In message , Phil L
writes
WeeBob

It's unlikely that they are getting in through any drains, so i wouldn't
waste any more money following this particular dead end, the drains don't go
anywhere near the roof, if anything, they could terminate under the
suspended part of the floor and this area would be rat heaven. How are they
getting from there to the loft? - there's only one way and that's via the
cavity, which is probably uninsulated given the age of it. Get it filled
with fibre insulation and the rats will go away, they don't like it. There's
grants available and it would probably cost you less than hiring a piece of
equipment that doesn't work.

Concur on the drains but differ on the insulation.

We have had issues with mice particularly Woodmice. The problem started
with them moving a quantity of Walnuts from the garage to the loft over
our bedroom (about 25m).

The route appeared to be through the open cavity at the garage door
where it joined a timber barn. Through the cavity Rockwool insulation to
the soffit. Along the soffit to the main house then through/over the
insulation in the hall raised tie ceiling. This gave access to the house
attic where they proceeded to eat the Walnuts very noisily.

There were mice in the chalet bungalow loft I am extending. Again, up
the cavity through the insulation. Point of entry was probably where the
kitchen sink waste penetrated the brick exterior wall.

--
Tim Lamb

On Fri, 6 Jan 2017 09:46:06 +0000, WeeBob wrote:

I've got an IT background, with some 3d modelling, and I'm guessing that
with a few days practise, on a known area that I could get some useful
experience that I could then use to explore.

Maybe try another approach: track the rodents. UV-shiny dust is used, and UV
flashlights are plentiful on the bay, and net.

Yellow-tinted glasses make the fluorescence easier to see, an

First hit for a search for "fluorescent track rats"

http://www.lumidust.co.uk/


Thomas Prufer