bolthole

Hi T-Tree, Clay soil shrinks as it dries out. There's what you see at the surface, which is a big swing between summer and winter, but often clay soil can be very deep and it's the overall moisture content of that which matters. The surface will be muddy in the winter and rock hard in the summer, but deeper down and throughout the whole 'layer' this variability is far less. What does happen is that where land is built on, the amount of water that reaches the clay is generally reduced - houses have roofs and hard landscaped area (paths, driveways, etc), which takes water which would have previously gone into the soil away. So overall, it's fairly normal for clay land that's been built on to shrink. It's sort of pot luck but generally, you'll see a bit of settling in a building on a clay soil. This is the lintel cracks I mentioned. Houses have gardens and people plant trees in gardens to make them look nice, amenity, fruit, etc... so after the building hapens, there's then a period where people plant trees and patches of this land where those trees go are subject to more drying - especially with very vigorous, quick growing trees, the area around a tree will become drier and therefore the soild around the roots will tend to shrink more, and more quickly. For example, I have a fairly mature Laylandii near the back corner of my bungalow. We live on a flood plain on deep clay. That corner of the bungalow has a big-ish crack, not a wide crack, but nevertheless noticable. We asked our builder and he says that the rule of thumb is, if you can't get your fingers in the crack, there's nothing to worry about! Not sure about that, but he knows more than me. The ground under that corner has shrunk a bit more than the rest and that back corner of the building has dropped a bit... enough to open up a crack. We have a bit of very mild cracking elsewhere in the property, but this corner is worse. If we remove this tree, the bit of garden where it was will become 'wetter' again... so the soil where the roots are will expand. Proably all that will happen is that the crack will close up again, because the tree came after the house. It's quite a complicated subject and if you have any major concerns you should speak to a structural engineer... but if you have a house which is built amongst existing trees, on clay soil, and you remove these trees the soil will become wetter and expand. This is 'heave'. Say you house is completely surrounded by trees, and they were mature when you built the house, removing them would make the soil all around your house expand and probably you'd not notice anything. It would 'heave evenly'. Maybe. If you had the same scenario but say two big trees at one corner and you removed them, the soil there would expand and that corner of your house would be lifted and... you'd probably get cracking, or worse. With the original poster, I'd be concerned about that conservatory - if it was added on after the house was built, and that big old tree is removed, and they're on clay, there might be some heave! Probably the house will be fine... but it might have a bit of cracking already. Imagine you've got a big gingerbread house and you try and pick it up... if you can get a tray under it you'll probably be fine, if you get your fingers under one corner, it's going to end in tears!!

This is probably only a big worry if you're on clay soil. Where are you in the UK? Are there any existing signs of subsidence around the house? Eg. minor cracking around wondow lintels? Do the trees pre-date the building of the properties (I kind of doubt it, but it's worth an ask!)

Hi All, I'm trying to find a LOLER examiner in the Aylesbury area who can inspect our climbing and rigging kit. This isn't for Arb kit, but for Tower/Mast climbing and rigging kit. Not massively different and indeed the inspector at F R Jones and Son has said that they're happy to do it. Our premises are in Aylesbury and we'd really like to save the time, money and unnecessary carbon generation involved in delivering/collecting and/or posting it off. We'd like someone who could come to our premises and do it all on-site. Can anyone recommend someone? Thanks.

Yup.... it's running properly again. Now... that starter...

Quick update - changing the filter did seem to fix it, but it stopped again after about 10 minutes running on idle. I checked the vacuum operarated fuel pump by removing the spark plugs, removing the pipe that leads to the carb and replacing it with a length of clear plastic tubing; I then turned the engine over with the starter cord with the clear tube tucked into the back of the big red emergency stop button on top of the infeed chute. The pump did indeed push clean petrol up the tube against gravity. Then I took the air filter off, removed the two 10mm bolts in the top of the carb which held in the filter bracket and removed the filter seat. This allowed me access to the top of the carb, which could be removed with 4 x screws. The float valve just lifts out, but watch out for the float valve needle thing which is very loosly held and easily dropped. A quick look in the top of the carb showed it to be full of crap. I took the carb off completely which involves removing the big side cover, various brackets and the inlet manifold - all pretty straightforward) and blew out all the air ways and jets with the air line. It's almost back together now so I'll update the post when I have tried to start it.

Thanks! I'll let you know how I get on...

Yeh... I had to bypass the belt cover safety cut-out. Trouble is with these mods is that you do them and then forget how it should have been originally!!!

I'll check the starter motor terminals next. The energiser is getting 12V - I pulled the yellow terminal off and put the meter between it and the spade connector.

I was advised to warm it up before using it at load and I've also got into the habit of leaving it running at idle for a minute or two before switching off. Thanks for the tip though.

Looks like a sensible next move... thanks.

Nah... it's all clean. Had that before!

I'm still struggling a bit with this starter issue - do they get jammed at all? The battery is good, the terminals are shiney-clean and greased, all the electrics seem okay. How does the starter get 'switched on'? Is it that grey relay-looking thing? I think the key-operated switch is working okay because it cuts the ignition and if turned to the third position (to electric-start) something does happen... anyone know about this?

Well... it already is... looking at selling it later in the year and don't really want any bodges when it comes to that...

Yup - that's the badger. Tweeked the throttle cable a bit too - it wasn't bringing the revs up until the lever had travelled about a quarter or so of it's movement.