Tree roots lifting concrete paving. Is it fine to expose the soil?

[botchedashtree]

My garden is completely concrete and over the years about three trees have caused it to crack, split and even lift up so I'd like to get rid of some of the concrete and grow some nice wildflowers instead. My main concern is whether it is okay to do so.

 

I currently only have one mature ash tree and I believe its roots are the main culprit in lifting up the paving but as you can see in the photos there used to be a horse chestnut which burst open the ground and a smaller unknown species which caused cracks of its own. The concrete layer is roughly 2-4 inches thick and I'm assuming the ash tree's roots are growing right underneath, so if I remove the layer and expose the soil would the roots be okay? Or should I spread a 1 inch layer of multipurpose compost to give some protection? Additionally, I want to dig a 2 square metre area of soil out to create a wildlife pond so what depth would be okay to dig to without damaging the roots? - the pond would start about 3.6 metres from the trunk.

 

I lifted a large slab up where the horse chestnut used to be and found some 1 inch thick roots but I don't know which tree they belong too. Weirdly though, I lifted another slab opposite it and no roots were exposed, just soil; however I didn't dig further. As the soil is compacted from being under concrete for over 20 years I would need to rake it a bit to loosen it, will this be okay to do?

 

As for the tree itself it is around 100 years old and was disfigured in November by a cowboy so the health is questionable but I want it to live - I made a previous post about this situation if you want more information. I want to grow some smaller trees though in the new soil just in case it dies so if my idea is sound then I can go ahead.

[Khriss]

1 hour ago, botchedashtree said:

My garden is completely concrete and over the years about three trees have caused it to crack, split and even lift up so I'd like to get rid of some of the concrete and grow some nice wildflowers instead. My main concern is whether it is okay to do so.

 

I currently only have one mature ash tree and I believe its roots are the main culprit in lifting up the paving but as you can see in the photos there used to be a horse chestnut which burst open the ground and a smaller unknown species which caused cracks of its own. The concrete layer is roughly 2-4 inches thick and I'm assuming the ash tree's roots are growing right underneath, so if I remove the layer and expose the soil would the roots be okay? Or should I spread a 1 inch layer of multipurpose compost to give some protection? Additionally, I want to dig a 2 square metre area of soil out to create a wildlife pond so what depth would be okay to dig to without damaging the roots? - the pond would start about 3.6 metres from the trunk.

 

I lifted a large slab up where the horse chestnut used to be and found some 1 inch thick roots but I don't know which tree they belong too. Weirdly though, I lifted another slab opposite it and no roots were exposed, just soil; however I didn't dig further. As the soil is compacted from being under concrete for over 20 years I would need to rake it a bit to loosen it, will this be okay to do?

 

As for the tree itself it is around 100 years old and was disfigured in November by a cowboy so the health is questionable but I want it to live - I made a previous post about this situation if you want more information. I want to grow some smaller trees though in the new soil just in case it dies so if my idea is sound then I can go ahead.

Yer, pretty knackered concrete, i would gently take it up piece at a time and immediately cover roots with soil   sand mix to stop drying out. You want aeriated soil over roots as they need air just as much as water. Then decide yr garden n layout. K

Edited February 16, 2021 by Khriss
( Dont rake over the top of the roots thou !)

[botchedashtree]

1 hour ago, Khriss said:

Yer, pretty knackered concrete, i would gently take it up piece at a time and immediately cover roots with soil   sand mix to stop drying out. You want aeriated soil over roots as they need air just as much as water. Then decide yr garden n layout. K

Would a 1 inch layer be enough to stop them drying out?

[Khriss]

52 minutes ago, botchedashtree said:

Would a 1 inch layer be enough to stop them drying out?

More than that really but if yr gonna mulch over with some sort of organic material or what ever you use for yr paths or borders, will depend where it goes and depth will be how much leveling yr wanting.  The point is dont leave the roots exposed. K

[botchedashtree]

1 hour ago, Khriss said:

More than that really but if yr gonna mulch over with some sort of organic material or what ever you use for yr paths or borders, will depend where it goes and depth will be how much leveling yr wanting.  The point is dont leave the roots exposed. K

Oh okay I will make sure they're completely covered. Thanks for the advice

[JaySmith]

A good idea that you are considering removing the concrete, especially if the tree is already ‘stressed’ by the poor pruning it will be using its energy and stores to deal with that. Giving it a little helping hand may be what’s required.

I’ve done something similar on a mature Yew tree that had been concreted around. We gently broke up the concrete trying not to damage the roots, it’s important to not damage the small fiberous ones that take up water and nutrients as well as the larger ones that provide anchorage. Some of the roots we were dealing with were very near the surface so hessian webbing was used to protect them and a layer of mulch used over the top. The hessian was removed at a later date. This was done in the summer and we didn’t want the roots to be scorched so the webbing was recommend.

At the end of the day as long as the roots aren’t left exposed to the elements or direct damage occurs to them then removing the concrete can only have potential benefits to the tree. I’d use a well rotted mulch/soil mix to allow water, air and nutrients to pass through. Just don’t use freshly chipped wood chip if poss