A sunday morning puzzler

[Gary Prentice]

Morning folks, I've a situation that is puzzling me so offer it for your consideration and suggestions.

 

A curious phone call led me to visit a property yesterday.

 

The house is a large 1800's property over three floors with a later two story plus cellar extension built of stone. Adjacent to the side extension is a shared driveway (with the adjacent property) that inclines upwards from the road before forking: one way to my clients semi-below ground level garage, the other to steps leading alongside the neighbouring property and to the rear gardens.

 

Above the drive, on top of a 4 foot retaining wall is a triangle of level land with a 1m dbh mature sycamore. To the rear of the clients property a cobbled path leads, with a slight decline and a couple of steps, to a small rear yard and the kitchen door. The kitchen is floored with vinyl tiles. No information is available about the construction of this floor but it is thought that there is no cellar below.

 

One area of the floor has recently raised slightly, an area about 250-300mm by maybe half that, creating a small ridge and the tiles are showing minor cracks. In fact it has all the appearances of tarmac being lifted by a tree root!

 

From this area to the tree is approx 10-12m. From the base of the tree to the retaining wall to drive level is maybe 2m (4ft drop to drive) The kitchen floor is approximately one and a half metres below the base of the tree.

 

Three years ago, a sewer/top water pipe running down the drive had to be cleared of roots (some rotary cutting device was inserted), but no other information is available.

 

One idea as to the cause I have, is that if the floor is wood and if there is a water pipe leaking and wetting the boards localized swelling may be occurring. A lot of 'ifs' I know and I doubt this is the case myself.

 

I have suggested that, as the floor will need to be repaired anyway, initially the tiles are removed along with whatever lies beneath and the cause identified. If it is indeed a tree root, photo's are taken, the root severed and preserved and maybe a sample sent for identification. The tree is owned by the other property which is vacant due to the demise of the owner.

 

Overall, the distance and physical barriers/changes in elevation suggest that roots are not the cause, but I can't image what else would cause such localised structural movement.

 

The client has agreed to advise me the results of the excavation in the kitchen, but for now, I would be interested in others thoughts, experiences etc.

[Sussex Groundie]

At least this is not another "guess what happened to me thread"

 

I think the only answer is as you say to take up the floor and see whats going on, ruling out burst pipe , natural movement, it is an old property with cellars etc.

 

I have 2 estates with 1800 period properties, wells in the cellars, all sorts of things going on underground. Another house had to have 19 tress felled round it as it was going down like the Titanic at one end, guests complained of toilet doors coming open whilst "on the throne" .

 

Hope it all turns out ok and you get some work out of it, even for being sympathetic to their problem.

[Gary Prentice]

At least this is not another "guess what happened to me thread"

 

I think the only answer is as you say to take up the floor and see whats going on, ruling out burst pipe , natural movement, it is an old property with cellars etc.

 

I have 2 estates with 1800 period properties, wells in the cellars, all sorts of things going on underground. Another house had to have 19 tress felled round it as it was going down like the Titanic at one end, guests complained of toilet doors coming open whilst "on the throne" .

 

Hope it all turns out ok and you get some work out of it, even for being sympathetic to their problem.

 

Guess what happened to me? I went to this house and there was a raised ridge in the kitchen floor:biggrin:

 

It's certainly intrigued me. I wouldn't like to form a conclusion, even to a 'balance of probability' degree as to the cause. At the moment, I doubt that a burst pipe could cause a floor board to swell to this extent. The raise in level is too distinct and abrupt ( and too large).

 

The lack of other causes, that I can envisage, is leading me towards the tree root option - but, I still feel that this is unlikely. I don't know!

[felixthelogchopper]

First signs of a portal to Hades? What species were the tree roots removed from the pipe? It was a tree and not Japanese Knotweed?

[Gary Prentice]

First signs of a portal to Hades? What species were the tree roots removed from the pipe? It was a tree and not Japanese Knotweed?

 

More like the stomach bursting scene in Alien.

 

Sorry no information on the pipe, but no JK present that I saw. There's a large-ish Rowan to the front of the adjacent property that may be a factor. The down pipe from the garage roof enters an underground culvert that I suspect joins a wastewater system. Possible entry point for the sycamore, but only a presumption

[peatff]

Where is the house and is the floor the original quarry tile ? If so they were bedded on nothing substantial, ours were on clinker from the local foundry which is notorious for moving on it's own. Our kitchen has a low ceiling and the floor rose so much in the middle that my head touched the light fitting, the house was built around 1860.

[felixthelogchopper]

More like the stomach bursting scene in Alien.

 

Sorry no information on the pipe, but no JK present that I saw. There's a large-ish Rowan to the front of the adjacent property that may be a factor. The down pipe from the garage roof enters an underground culvert that I suspect joins a wastewater system. Possible entry point for the sycamore, but only a presumption

 

Where I used to live (Edwardian terraces c1905), one of my neighbours had a problem with a blocked downstairs loo which turned out to be caused by the roots of a Willow 4 houses away. Maybe one of the trees there is feeling adventurous but the varied ground levels make it a bit unusual.

[woody paul]

Strucual engineer's job to work out problem then call tree man in if trees a problem. But they can get it wrong.

[peatff]

A house we looked at years ago had problems with raised floors because of subsidence. Is there any evidence of cracking round the door frames and windows ? It had sunk slightly at both ends and a supporting wall in the middle was holding the centre of the floor up so the door above it would only open half way before it grounded.

[Robbo90]

You don't say what part of the country the house is located in? If it in the northwest..ish midlands it could be red ash but unlikely if the floor was laid in the 1800's and not touched since. Red ash was used as infill for foundations and the like as it was cheap or free. The ash came from foundries and gas works, anywhere that uses large fires. Red ash is high in sulphur and when freshly laid goes off like concrete but if it starts to get wet, swells and can do what you are possibly describing. A test costs about 200 quid