How deep should a sub-base be for a patio? Dig a depth of around 150mm across the whole area, making sure the soil is evenly compacted. Then tip in the sub-base, raking it into a consistent depth of 100mm.
Can you lay new paving over an old sub base?
In such cases, the tarmac can usually be stripped off, the sub-base checked and re-levelled if required, and the new paving can be laid over the old sub-base. A finished sub-base should not deviate from the correct level by more than 10mm, and should reflect the final profile of the paving.
How thick should a sub-base be?
The sub-base material should be spread out in layers no thicker than 150mm and roughly levelled with spades, rakes or similar. Where a sub-base needs to be greater than 150mm in depth, it should be built-up as a series of layers, each being 150mm or less and thoroughly compacted before placing, levelling and compacting the next.
What is a sub base in paving construction?
Photo: The Outdoor Room The sub-base is the main load-bearing layer of paving construction. A well-designed sub-base should evenly spread the load of traffic, whether pedestrian or vehicular, down to the sub-grade, also known as the formation level.
What is the best design for a sub-base?
A well-designed sub-base should evenly spread the load of traffic, whether pedestrian or vehicular, down to the sub-grade, also known as the formation level. Best practice usually stipulates a geotextile non-woven membrane (e.g. Terram 1000), which acts as a filtration/ separation layer between the subgrade and sub-base.
How thick should a sub-base be for a patio?
The depth of the mortar bed should be approximately 35-40mm deep. Ideally starting from a right angle or straight edge, place the slab down. Gently tap with a rubber mallet or press down with your hands and use a spirit level to ensure to make sure the slab is level and in line with your proposed design.
What can I use as a sub-base patio?
2:143:24How To Prepare A Patio Sub-Base - YouTubeYouTubeStart of suggested clipEnd of suggested clipSinking compact down to 60 millimeters below the string. Line you may need to top up with more stoneMoreSinking compact down to 60 millimeters below the string. Line you may need to top up with more stone. So just check in 100 millimeters of sub base leave 60 millimeters for the bedding mortar.
How do you compact a sub-base for a patio?
0:231:27How To Get Perfect Sub Base Compaction - YouTubeYouTubeStart of suggested clipEnd of suggested clipAnd already we've got to a nap bricks below down course. So if I give it a little bit more of it toMoreAnd already we've got to a nap bricks below down course. So if I give it a little bit more of it to very severe compaction organ and up to about three bricks below that force. That's more than ample.
How deep does a sub-base need to be?
How deep should my sub-base be? Generally, a flexible sub-base of unbound material needs to be at least 100mm deep, as does a bound sub-base of CBM/HBM. For bitumen-bound material, then 50mm is a typical minimum thickness.
Can I use broken slabs as a sub-base?
It will be fine.
Can you use gravel as a sub-base for patio?
This unstable structure means all gravels are not suitable for patio sub bases. The typical reason for wanting to use gravel for a patio base is recycling existing materials. It is much more expensive to skip used gravel and buy in fresh sub base.
What is sub-base material?
Ideally a small wacker plate would be beneficial to compact it but a hand tamp will do an ok job although you'll have arms like popeye when you finish.May 25, 2020Compacting MOT type 1 and sand manuallyhttps://community.screwfix.com › threads › compacting-...https://community.screwfix.com › threads › compacting-...Search for: Can you compact sub-base by hand?
Can I lay patio on soil?
Each time a vehicle pulls into a garage and stops, that action creates a plate compactor effect. If the backfill under the slab has not been properly compacted, the structural fill will eventually settle, leaving voids.Q&A: Is It Necessary to Compact Slab Sub-Base? - JLC Onlinehttps://www.jlconline.com › how-to › foundations › q-a-is...https://www.jlconline.com › how-to › foundations › q-a-is...Search for: What happens if you dont compact sub-base?
Can I use ballast as sub-base?
You'll want to ensure that the water penetrates the entire depth of the sub-base material from top to bottom, but you'll want to avoid flooding the surface. If the base is too wet, you'll find that your plate compactor sinks too deep into surface. If this is case, allow the aggregate to dry out.Feb 9, 2018The Importance of Adequate Compaction When Installing an ...https://neograss.co.uk › compaction-installing-artificial-lawnhttps://neograss.co.uk › compaction-installing-artificial-lawnSearch for: Should you wet sub-base before compacting?
Can I lay slabs on sand?
Sub-base material is produced by crushing either limestone or granite rock. The sub-base is designed to evenly spread the load on traffic bearing areas such as pavements and roads. Made up of a load-bearing layer of aggregate, the sub-base is laid on the sub-grade layer below.Sub-base material selection for MetroPave | Naylor Drainagehttps://www.naylor.co.uk › sub-base-material-selectionhttps://www.naylor.co.uk › sub-base-material-selection
What is a 75mm compacted thickness?
75mm compacted thickness of DTp1 or of 50mm crusher run, compacted with a vibrating plate compactor (Wacker plate) or vibrating roller, if space permits. Both these items are available from local hire centres. A reasonable alternative is to compact the material by dropping a sledge hammer or asphalt punnel directly down onto the material, using the weight of the tool to aid the compaction. A compacted sub-base should not move when you walk upon it.
How long does it take for concrete to set?
A 'slab' of mass concrete, usually 100mm or 150mm thick is spread and compacted, then allowed to set. A few days later (2-7 days, depending on time of year and weather conditions), the paving is laid on a bedding material over the now solid concrete. A medium strength concrete is used in most applications.
How thick is DTp1?
This is exactly the same as the Light-Medium Duty sub-base above, except it is 50mm thicker. 150mm of DTp1 is used, and this may be compacted as two 75mm layers or one 150 mm layer. Compact thoroughly and make sure the final surface is 'tight' before continuing with the bedding material.
What is sub base paving?
The sub-base layer is often the main load-bearing layer of a pavement. It is designed to evenly spread the load of the paving, and any traffic thereon, to the sub-grade below. A well-constructed sub-base will aid drainage and prevent settlement and channelisation - the phenomenon common on cheap installations of block paving, where two 'ruts' develop in the paving. These 'ruts' are caused when a car travels over the same line of paving to the garage, every morning and every night. Channelisation is also apparent on carriageways, particularly at the approach to traffic lights and on upward gradients. The sub-base is intended to prevent channelisation and settlement.
What is MOT1 in Ireland?
The full title is "Type 1 granular sub-base to the Department of Transport Specification for Highway Works" It is still referred to as MOT1 (the old Ministry of Transport) or even the more inaccurate "40mm to dust". In Ireland it is usually known as "804", a name derived from the fact that the full specification is to be found in clause 804 of the National Roads Authority's Specification for Road Works.
What to do if sub base isn't required?
If your contractor tells you that a sub-base isn't required beneath your new drive, then ask how the sub-grade (soil beneath drive) is going to spread the load of the paving and what guarantee is offered with regard to settlement. Alternatively, get a different contractor to give their opinion.
Can tarmac be stripped off?
In such cases, the tarmac can usually be stripped off, the sub-base checked and re-levelled if required, and the new paving can be laid over the old sub-base. A finished sub-base should not deviate from the correct level by more than 10mm, and should reflect the final profile of the paving.
What are the advantages of paver patio base panels?
The panels have the added advantage of providing an insulating layer that reduce s problems caused by soil that thaws and refreezes. And finally, paver patio base panels have built-in channels and holes to drain water to the sand layer below.
How many paver base panels do I need for a patio?
But there’s an easier way. Let plastic panels take the place of the gravel base. For that same patio, you would need only 24 paver base panels weighing a total of about 30 pounds to replace the 2-1/2 tons of gravel. Paver patio base panels are made from lightweight high-density polypropylene. The panels typically have tongue-and-groove ...
Why is the weight of a person walking on the patio distributed more widely?
The answer is that the panels spread out the load, so the weight of a person walking on the patio is distributed more widely. Distributing the load puts less pressure on the soil and prevents the paver bricks from becoming uneven.
How deep should I put gravel on a patio?
A traditional base for a paver or stone patio is a 6-inch-deep layer of compacted gravel. For a typical 10 x 12-foot patio, that means carting away about 2-1/2 tons of soil, and hauling in the same amount of gravel. But there’s an easier way.
How can I speed up sod removal?
Pro tip: You can speed up sod removal by renting a sod cutter. Pro tip: You also must remove soil evenly and leave a flat surface, as there’s no thick layer of gravel to make up for uneven ground. After digging and grading, there shouldn’t be more than about 1/2-inch variation in flatness over the area.
What is the purpose of landscape fabric?
Note: The purpose of the landscape fabric is to prevent the sand from mixing in with the soil. But it’s important to use a non-woven fabric, as woven landscape fabric isn’t very permeable and can trap water under your patio. Look for fabric with at least a 20-year life span. Step 4.
What is a sub base for paving?
In the good old days, a paving sub-base used to be ‘hardcore’ comprising old bricks and broken up lumps of concrete, all of which were of varying sizes and shapes. Although often strong enough as a material, it was the random sizes that caused voids, which had to be blinded in with gravel afterwards. The irregular sizes often led to weak spots that would eventually cause sinkage or cracking of the paving above.
What happens if a sub base isn't correct?
If the sub-base isn’t correct, a beautifully laid terrace may well become useless in a relatively short space of time. Failed paving construction can very often be put down to the sub-base being the wrong material, an insufficient depth or being poorly installed.
What is the most common type of aggregate sub base?
The most common granular aggregate sub-base is DoT (Department of Transport) Type 1 and Type 3 Limestone. They are both crushed stone: Type 1 has a maximum permitted top size of 63mm, graded down to dust; and Type 3 is an open-graded 40mm unbound mixture with a reduced amount of fines.
What is the main load bearing layer of paving?
The sub-base is the main load-bearing layer of paving construction. A well-designed sub-base should evenly spread the load of traffic, whether pedestrian or vehicular, down to the sub-grade, also known as the formation level.
Can a vibrating plate compactor be used on a patio?
A vibrating plate compactor may be suitable for patios and paths, but a much heavier-duty vibrating roller will be required for a driveway.
Is concrete sub base more expensive than granular?
A concrete sub-base is a lot more expensive than a granular one , but if it’s well laid and the stone is well calibrated, or if you’re using the increasingly omnipresent porcelain, the laying of the finished surface is far quicker, as you’re effectively gluing the paving to the base using a 5mm bed of exterior adhesive.
Is scalping type 3 or 2 porous?
Both are porous, but Type 3 is becoming more and more popular if the finished surface is to be free draining or have a permeable jointing material. There are also Type 2 and scalping sub-bases, which are usually 40mm down to dust, but with a higher percentage of fines, therefore having less load-bearing capability.
