Frequently Asked Questions
Sinkholes And Mines
Q: How do sinkholes form?
Water from the surface or water in an aquifer must got somewhere and it usually chooses to follow the path of least resistance. If you have limestone and in some cases other minerals beneath you may be susseptable to sink holes.
Water contains acids which react with minerals such as limestone and over millions of years will errode the limestone while the aquifer travels through it. Some times the aquifer is verticle and sometimes it is horizontal. Either way the limestone is be erroded by the water and an underwater cave is formed. Then over time the water level drops and the cave becomes aerated and is just a void of space. In a lot of places the surrounding area is strong enough to hold the roof of the cave up but there is rare cases in UK which the roof collapses and you are left with a collapse sinkhole which are usually reported in the news.
Q: Is there more then one type of sinkhole?
Yes the most common is a solution sinkhole which is just a dip in a landscape. What happens is a crack in the rock below opens up and when it rains the water washes the ground into this crack. There is no collapse, the ground above the crack simply.... sinks into the hole. The ground above if it is grassed will look exactely the same but will just look like a dip in the ground. These are not dangerous like a collapse sinkhole.
The other type which you only hear about in the papers is a collapse sinkhole which is explained above and can be extremely dangerous.
Q: How can i find out if a sinkhole is underneath me?
Well there is a few ways to tell.
Contact us with your address and we will have a look at the geology beneath you, This will be one of the most important ways to check. We can also supply a geological survey of your property if you want the peace of mind and you can also use it for your home insurance.
you can also instruct us to drill on your property which will tell us if there is a void beneath you and in the rare circumstance that there is, Pumping and filling the void with foaming concrete will stabalise the property.
Q: What else can cause a sinkhole?
Mines. Abondoned mines are the main source of sinkholes. The worst thing is abandoned mines are every where in the UK and unless you knew where they were you could be sat above one. Please contact us and we will be able to check if you property could be effected by one.
Q: Is living above a mine dangerous?
No. Mines were designed to be extremely supportive and although we see mines as being held up by wooden support beams in all the movies, they are not. Mines are naturally created by running water all the time so mankind digging one will not be much different. The surrounding area of the mines are usaully extremely strong that the rock can support the weight of above.
If you have a mine that is close to the surface then this is when you will find the ground and rocks above the mine will be weaker.
Authorities are always checking the condition of all known mines and if there is a concern they are speaking direct with people living above them. If you are concerned you may have problems please get in touch with us or mine specialists.
Q: Is it a well or sinkhole?
Many people that suddenly find the ground collapsing during flooding, gardening or when having works done to their property such as an extension first think they have a sinkhole but in a lot of cases they are actually wells. These could be brick lined or naturally dug wells and left unlined. If you think you have a well or sink hole please get in touch with us.
Q: Can i use a sinkhole or what to do with one?
If you speak to anyone about a sinkhole they will certainly see just the word sinkhole extremely dangerous and will not want much to do with it. Insurance companies are ever worried about them and many will say the only solution if to fill them in.
If the sides are shored up correctly and the bottom drilled and pilled to insure it is safe there really is no reason not to use it. Obviously there is major cost involved and also the danger of more collapse.