Ask a tradesperson

Landscape Gardening

Paving over existing paving slabs

I have approx 280 450mmx450mm paving slabs, underneath is a base of hardcore I think then sand. I've had a garden man to quote for repaving, he says he wants pave over the existing slabs on a cement mix. As far as I know the ground is ok. Am I looking at trouble?

11 Answers from MyBuilder Landscape Gardeners

Best Answer

I don't agree with these comments. How long has the paving been down? If it's years then its had a long time to compact and settle. You could break the slabs with a sledge hammer to further compact if you feel subsidence is a problem and then cast a solid, steel reinforced concrete pad over the whole area, building off this if the finished levels allow this raise in height. Sometimes this approach beats the digger/grab hire/rebuilding of the base scenario.


Answered 9th Dec 2015

I think you should get somebody in that is qualified to have a look at it the slabs anytime a new area is paved you should have at least 200mm a hardcore base of mot we recommending all slabs should be laid full cement base


Answered 26th Jan 2017

Get someone who knows what he is doing . Who is to say the sub base underneath is sound enough . If he is too lazy to lift the existing paving then he will be sure to cut corners elsewhere . Sounds like he is trying to make quick ££££ and rip you off . Any good honest tradesman will tell you the most important part of any paving is getting the subbase right


Answered 1st Feb 2014

You should remove all old paving and sand and reinforce hard-core with TYPE 1 MOT .It also depend on which type of paving you are laying. Example all natural sandstone should be laid on a full cement bed. Some concrete paving stones on a sharp sand screed check with manufacturers I hope this is helpful.Thornton McLaughlin Castle paving


Answered 24th May 2016

Simple answer is yes.

Find someone who knows what he is doing as this is all wrong.

If you want more info let me know.


Answered 30th Jan 2014

Absolutely agree with the other tradesmen. He needs to remove the existing paving. If you need more information you are very welcome to contact me.


Answered 11th May 2015

Old Paving should never be paved over it is not a suitable base, it needs excavating and Type 1 MOT Base installing, foundation and prep is key to any job, kind regards Steve


Answered 5th Nov 2019

Depending on how long the existing slabs have been there I would smash compact and maybe look for some crushed concrete to bed in even further but the answer to your question is if the foundation has been there for more than two years it has had plenty of time to settle and should not move anywhere so just for extra precaution break up into smaller pieces add crushed Concrete and compact


Answered 3rd Dec 2020

Definitely not! Never ever lay paving over the top of an existing patio and certainly not if u didn’t see it installed originally u would never know the ground underneath was prepped properly unless it was lifted all paved Patios shud be lifted and fresh sub base mot installed and whacked prior to laying sounds to me he’s tryna make a quick quid out of you


Answered 4th Aug 2022

I would highly recommend not proceeding that way and I would recommend taking up all the old patio and inspect the existing sub base ensure that it’s solid.


Answered 14th Jun 2023

-Rip up old paving and excess debris/hardcore.

-Ensure finished height of paving is 150mm below DPC and that you have at least 75mm of compacted scalpings/MOT below the slabs, with a minimum mortar bed of 30mm.


Answered 20th Jul 2023

Post your job to find high quality tradespeople and get free quotes

Can’t find an answer? Ask a new question

Question Categories