New Patio on Old Concrete
 

Good Afternoon, I have not posted here before but as a novice gardener atemmpting my first big project I would really appreciate some advice. I have just moved into a property with an old, cracked and slightly unevenr concrete patio. I want to relay this with flags but am unsure whether I would need to rip up the old patio, screed it level or simply put down a good layer of sand to level it off before laying slabs... Anyone have any hints and tips?

New Patio on Old Concrete
 

In article m,
Tom Redpath writes:
| Good Afternoon, I have not posted here before but as a novice gardener
| atemmpting my first big project I would really appreciate some advice.
| I have just moved into a property with an old, cracked and slightly
| unevenr concrete patio. I want to relay this with flags but am unsure
| whether I would need to rip up the old patio, screed it level or simply
| put down a good layer of sand to level it off before laying slabs...
| Anyone have any hints and tips?

The latter is fine, if increasing the height by 3-4" will not cause a
problem.


Regards,
Nick Maclaren.

New Patio on Old Concrete
 

Nick Maclaren wrote:
In article m,
Tom Redpath writes:
Good Afternoon, I have not posted here before but as a novice
gardener atemmpting my first big project I would really appreciate
some advice. I have just moved into a property with an old, cracked
and slightly unevenr concrete patio. I want to relay this with
flags but am unsure whether I would need to rip up the old patio,
screed it level or simply put down a good layer of sand to level it
off before laying slabs... Anyone have any hints and tips?

The latter is fine, if increasing the height by 3-4" will not cause a
problem.


Yes and no! Sand alone will not make a secure long term base - it will wash
out and ants will move it.

Better to either use a proper dry mix of sharp sand and cement -

pk

New Patio on Old Concrete
 

In article ,
"PK" writes:
|
| Yes and no! Sand alone will not make a secure long term base - it will wash
| out and ants will move it.

Er, no. See Cormaic's pages. When done right, it will last for
decades and often centuries. For millennia, you need a better
construction.

| Better to either use a proper dry mix of sharp sand and cement -

Which is quite likely to crack in its turn, thus leaving you with
an even thicker mass of concrete to deal with. Also, if you have
any services underneath, or don't know that you don't, laying on
sand allows access with low hassle.


Regards,
Nick Maclaren.

New Patio on Old Concrete
 

In article m,
Tom Redpath writes:
| Good Afternoon, I have not posted here before but as a novice gardener
| atemmpting my first big project I would really appreciate some advice.
| I have just moved into a property with an old, cracked and slightly
| unevenr concrete patio. I want to relay this with flags but am unsure
| whether I would need to rip up the old patio, screed it level or simply
| put down a good layer of sand to level it off before laying slabs...
| Anyone have any hints and tips?

The latter is fine, if increasing the height by 3-4" will not cause a
problem.


Regards,
Nick Maclaren.

New Patio on Old Concrete
 

Nick Maclaren wrote:
In article m,
Tom Redpath writes:
Good Afternoon, I have not posted here before but as a novice
gardener atemmpting my first big project I would really appreciate
some advice. I have just moved into a property with an old, cracked
and slightly unevenr concrete patio. I want to relay this with
flags but am unsure whether I would need to rip up the old patio,
screed it level or simply put down a good layer of sand to level it
off before laying slabs... Anyone have any hints and tips?

The latter is fine, if increasing the height by 3-4" will not cause a
problem.


Yes and no! Sand alone will not make a secure long term base - it will wash
out and ants will move it.

Better to either use a proper dry mix of sharp sand and cement -

pk

New Patio on Old Concrete
 

Nick Maclaren wrote:
In article ,
"PK" writes:

Yes and no! Sand alone will not make a secure long term base - it
will wash out and ants will move it.

Er, no. See Cormaic's pages. When done right, it will last for
decades and often centuries. For millennia, you need a better
construction.

Cormaic:
The flagstones can be bedded directly onto a coarse, grit sand bed, approx
40mm thick.
DO NOT USE BUILDING SAND - it is to soft and can become 'fluid' when
waterlogged, consequently moving beneath the flags, causing settlement.
The bedding material can be stiffened by the addition of a small quantity of
cement, around a 10:1 mix is adequate. This is useful when working in wet
areas, or where the movement of ground water could lead to bed migration,
and we find it useful beneath the thinner patio flags as it gives the
finished pavement a bit more solidity. Refer to Mortars & Concretes Page for
details on a cementitious bedding mix.

I'd agree a professional paver using sand alone will do a robust job, a
first time amateur i'd alaway recommend a lean mix mortar to avond needing
to bed each slap to a firm level.

pk

New Patio on Old Concrete
 

In article m,
Tom Redpath writes:
| Good Afternoon, I have not posted here before but as a novice gardener
| atemmpting my first big project I would really appreciate some advice.
| I have just moved into a property with an old, cracked and slightly
| unevenr concrete patio. I want to relay this with flags but am unsure
| whether I would need to rip up the old patio, screed it level or simply
| put down a good layer of sand to level it off before laying slabs...
| Anyone have any hints and tips?

The latter is fine, if increasing the height by 3-4" will not cause a
problem.


Regards,
Nick Maclaren.

New Patio on Old Concrete
 

Nick Maclaren wrote:
In article m,
Tom Redpath writes:
Good Afternoon, I have not posted here before but as a novice
gardener atemmpting my first big project I would really appreciate
some advice. I have just moved into a property with an old, cracked
and slightly unevenr concrete patio. I want to relay this with
flags but am unsure whether I would need to rip up the old patio,
screed it level or simply put down a good layer of sand to level it
off before laying slabs... Anyone have any hints and tips?

The latter is fine, if increasing the height by 3-4" will not cause a
problem.


Yes and no! Sand alone will not make a secure long term base - it will wash
out and ants will move it.

Better to either use a proper dry mix of sharp sand and cement -

pk

New Patio on Old Concrete
 

In article ,
"PK" writes:
|
| Yes and no! Sand alone will not make a secure long term base - it will wash
| out and ants will move it.

Er, no. See Cormaic's pages. When done right, it will last for
decades and often centuries. For millennia, you need a better
construction.

| Better to either use a proper dry mix of sharp sand and cement -

Which is quite likely to crack in its turn, thus leaving you with
an even thicker mass of concrete to deal with. Also, if you have
any services underneath, or don't know that you don't, laying on
sand allows access with low hassle.


Regards,
Nick Maclaren.

New Patio on Old Concrete
 

In article m,
Tom Redpath writes:
| Good Afternoon, I have not posted here before but as a novice gardener
| atemmpting my first big project I would really appreciate some advice.
| I have just moved into a property with an old, cracked and slightly
| unevenr concrete patio. I want to relay this with flags but am unsure
| whether I would need to rip up the old patio, screed it level or simply
| put down a good layer of sand to level it off before laying slabs...
| Anyone have any hints and tips?

The latter is fine, if increasing the height by 3-4" will not cause a
problem.


Regards,
Nick Maclaren.

New Patio on Old Concrete
 

Nick Maclaren wrote:
In article m,
Tom Redpath writes:
Good Afternoon, I have not posted here before but as a novice
gardener atemmpting my first big project I would really appreciate
some advice. I have just moved into a property with an old, cracked
and slightly unevenr concrete patio. I want to relay this with
flags but am unsure whether I would need to rip up the old patio,
screed it level or simply put down a good layer of sand to level it
off before laying slabs... Anyone have any hints and tips?

The latter is fine, if increasing the height by 3-4" will not cause a
problem.


Yes and no! Sand alone will not make a secure long term base - it will wash
out and ants will move it.

Better to either use a proper dry mix of sharp sand and cement -

pk

New Patio on Old Concrete
 

In article ,
"PK" writes:
|
| Yes and no! Sand alone will not make a secure long term base - it will wash
| out and ants will move it.

Er, no. See Cormaic's pages. When done right, it will last for
decades and often centuries. For millennia, you need a better
construction.

| Better to either use a proper dry mix of sharp sand and cement -

Which is quite likely to crack in its turn, thus leaving you with
an even thicker mass of concrete to deal with. Also, if you have
any services underneath, or don't know that you don't, laying on
sand allows access with low hassle.


Regards,
Nick Maclaren.

New Patio on Old Concrete
 

Nick Maclaren wrote:
In article ,
"PK" writes:

Yes and no! Sand alone will not make a secure long term base - it
will wash out and ants will move it.

Er, no. See Cormaic's pages. When done right, it will last for
decades and often centuries. For millennia, you need a better
construction.

Cormaic:
The flagstones can be bedded directly onto a coarse, grit sand bed, approx
40mm thick.
DO NOT USE BUILDING SAND - it is to soft and can become 'fluid' when
waterlogged, consequently moving beneath the flags, causing settlement.
The bedding material can be stiffened by the addition of a small quantity of
cement, around a 10:1 mix is adequate. This is useful when working in wet
areas, or where the movement of ground water could lead to bed migration,
and we find it useful beneath the thinner patio flags as it gives the
finished pavement a bit more solidity. Refer to Mortars & Concretes Page for
details on a cementitious bedding mix.

I'd agree a professional paver using sand alone will do a robust job, a
first time amateur i'd alaway recommend a lean mix mortar to avond needing
to bed each slap to a firm level.

pk

New Patio on Old Concrete
 

Nick Maclaren wrote:
In article ,
"PK" writes:

Yes and no! Sand alone will not make a secure long term base - it
will wash out and ants will move it.

Er, no. See Cormaic's pages. When done right, it will last for
decades and often centuries. For millennia, you need a better
construction.

Cormaic:
The flagstones can be bedded directly onto a coarse, grit sand bed, approx
40mm thick.
DO NOT USE BUILDING SAND - it is to soft and can become 'fluid' when
waterlogged, consequently moving beneath the flags, causing settlement.
The bedding material can be stiffened by the addition of a small quantity of
cement, around a 10:1 mix is adequate. This is useful when working in wet
areas, or where the movement of ground water could lead to bed migration,
and we find it useful beneath the thinner patio flags as it gives the
finished pavement a bit more solidity. Refer to Mortars & Concretes Page for
details on a cementitious bedding mix.

I'd agree a professional paver using sand alone will do a robust job, a
first time amateur i'd alaway recommend a lean mix mortar to avond needing
to bed each slap to a firm level.

pk