Do I need a membrane under my patio?

Asked By: Jerzy Zappia | Last Updated: 1st June, 2020
Category: home and garden landscaping
4.4/5 (1,089 Views . 45 Votes)
In the vast majority of light-use constructions (patios, driveways, footpaths, etc) there is absolutely no need for a membrane to be placed between sub-base and the bedding layer: it achieves almost nothing, as a well-selected sub-base material will have what we call a 'tight' or 'close' finish, that is, there will be

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Subsequently, one may also ask, do you need membrane under block paving?

There are two types of layers, sub-grade and sub-base. A sub-base would then need to be installed before laying the paving. Weed control membranes are not essential, however if you are aware of an area with invasive weeds or roots or excavated unreliable ground, a woven groundcover or membrane would be advised.

Secondly, what do you put under paving slabs? You will need

  1. Paving slabs.
  2. MOT type 1 hardcore or sub-base material.
  3. Sharp sand or All in ballast.
  4. Cement.
  5. Fine, kiln-dried block paving sand - for jointing 10mm or smaller joints.
  6. Building sand - for jointing larger joints.
  7. Long timber straight edge - for ensuring your sub-base is level.

In this way, should I put membrane under slabs?

I would advise taking at least another 2” of soil out, a minimum of 4-5” of MOT is standard for a patio, you don't need weed membrane as weeds won't grow under the patio only in the joints if they are not grouted properly.

Do I need a sub base for my patio?

The short answer is: if the pavement will be trafficked by vehicles, then yes, but if it will be foot-traffic only, then not necessarily. The type of paving or surfacing that will be used is one of the key factors in determining whether a sub-base will be required.

38 Related Question Answers Found

Do you need landscape fabric under pavers?

Some patio builders favor deterring weeds with a layer of landscape fabric, positioned at the bottom of the bed, under the gravel or between the gravel and sand layers. Further, nonporous and even porous plastic fabric can interfere severely with water drainage, making pavers slippery and washing away supporting sand.

Can I use gravel as sub base?

Gravel is fine as a sub-base providing its compacted well. If you do use gravel it needs to be restrained on all sides to stop it spreading. You would also need to lay the slabs on mortar as sand would simply drain away.

How do you prepare ground for paving?

Use landscaper's spray paint to mark the area directly on the ground (Image 2).
  1. consider thickness of paving stone. Fix Patio Height.
  2. make sure patio slope is consistent with gravel. Fill in with Gravel.
  3. screed sand before laying pavers. Screed Sand.
  4. snap chalk line and place pavers.
  5. cut odd pieces of pavers.

Can I lay slabs on sand?

Laying slabs on sand
Keep adding the slabs and ensure there's a gap of about 10-15mm between each stone. When you're laying the slabs, make sure you kneel on the sand rather than on the slabs you've already laid – the extra pressure may bed in the slabs too deep and make your patio uneven.

Can you use ballast as a sub base?


In some parts of the country, 'all-in ballast' refers to a mixture of gravel and/or small stone (<60mm) with sand, often used to make concrete. As such it should never be used for any critical concrete, such as floor or base slabs.

Does sharp sand stop weeds?

The answer traditionally was by using sand and cement, or if you required a more porous solution using simple sharp sand. The problems with these two solutions are sharp sand is actually a great place for weed seeds to bed. The process is quick, convenient and almost as easy as brushing in sand.

Can a patio be laid in the rain?

Laying a patio in heavy rain can cause real problems. The cement can become saturated causing level paving slabs to move and sink. Heavy rain is likely to wash the cement content out of mortar significantly reducing its strength.

Can you lay slabs straight onto soil?

Stick a bag of cement (or 2) in with the sand and lay a dry mix. I'd just dig out to the depth of the slabs plus a bit and level it out, compact the soil, level with sand and lay the slabs over the top butted up really tight.

What gap do you leave between patio slabs?


Lay each slab to level along the house and leave a gap of about 12 – 15mm between each slab. This is the optimum gap for making absolutely sure you can point the joints well. Any larger and they may crack, any smaller and it will be hard to get the mortar into the gap.

Should I leave a gap between paving slabs?

I'd recommend a 10mm gap between slabs. As for leaving a gap - it all depends on the edge style of the slabs. If they have an edge designed to mimic a natural stone product (uneven) then you'll need to go with the pointed gap.

Should patio go right up to house?

You can install pavers against your house foundation as long as it is the foundation itself. This means that you can lay the pavers against the concrete of your foundation as it rises from the earth. If you find your plans require laying pavers against vents, siding or other materials, choose another patio plan.

How do you lay a patio without concrete?

Although building your patio over a concrete slab helps to ensure it won't settle unevenly later, you can build a patio without cement. By laying flagstone, tile, brick or other sturdy, flat pavers on a well-prepared base, your patio will be less expensive and more water-permeable.

Can I lay paving slabs on gravel?

There are many shapes and sizes of paving slabs you could lay on gravel as a stepping stone. Concrete or stone, circular, square or oblong all make good stepping-stones and the method of laying them in gravel remains the same whatever type you want to use.

How do you lay a patio?


Here's how to lay a patio in 6 easy steps.
  1. Dig 150mm into your patio area.
  2. Lay a compacted sub-base of 100mm.
  3. Cover the area with 40mm of concrete mix.
  4. Lay paving slabs 15mm into the concrete with a 10-15mm gap.
  5. Leave to set for at least 24 hours.
  6. Fill the gaps between the paving slabs with concrete mix.

Can you dot and dab patio slabs?

This Is How Patios Used To Be Laid – Dot & Dab Method
The reason is the dot & dab method its self. Yes it will work, but it will not last know where near as long as full mortar bed patios last. The swollen ice will weaken the bond between the slabs themselves and the mortar and the stone will move over time.

Can you lay pavers on just sand?

Compacted concrete sand is then placed on top of this. A thin final layer of setting sand is the actual surface on which you place the pavers. Larger paving stones act like building footings. In other words, compacted sand can provide a sufficient base for a paver patio that's just going to have you walking across it.