Why Choose Mixed Size Granite Setts for a Driveway?
Mixed size granite setts combine the familiar rectangular layout of UK block paving with the strength and natural appearance of granite. Our Silver Grey Sawn & Flamed Granite Setts Project Pack includes three lengths, all 150 mm wide and 50 mm thick. Alternating these lengths creates a varied laying pattern with staggered joints, rather than continuous straight joints across the driveway.
Are These Granite Setts Similar to UK Concrete Block Paving?
Yes, in their rectangular proportions and laying style. Conventional concrete block paving is already familiar to UK homeowners and installers. Our mixed size granite setts follow the same practical design approach, but use natural silver grey granite with flamed upper surfaces and precision-sawn edges. The three sizes are specific to this project pack rather than a universal UK block paving standard.
Why Use Three Different Lengths with the Same Width?
Keeping all three sizes at 150 mm wide makes it easier to maintain straight courses, while the different lengths allow the joints to be staggered. This reduces long, continuous joint lines and produces a less repetitive appearance. Properly supported and jointed setts also benefit from the restraint provided by surrounding stones, bedding and edge restraints.
Should 50 mm Granite Setts Be Laid on a Rigid Mortar Bed?
For our 50 mm sawn granite setts used on domestic driveways, we recommend a properly designed rigid laying system with a full mortar bed and a suitable bonding slurry primer. The supporting construction must be appropriate for the ground conditions and anticipated vehicle loads. A low-absorption granite surface makes reliable bonding particularly important.
Why Compact MOT Type 1 Sub-Base in Two Layers?
Compacting the sub-base in separate layers helps achieve more consistent compaction through its depth. For example, a 150 mm compacted MOT Type 1 sub-base can be constructed in two 75 mm layers, with each layer thoroughly compacted before the next is added. This method is illustrated in UK natural stone sett installation guidance. The required overall thickness depends on the site and pavement design.
Silver Grey Mixed Size Granite Setts: Three Sizes, One Project Pack
Concrete block paving has been widely used on British driveways for many years. Its rectangular shape, manageable unit sizes and staggered laying patterns are familiar to installers and homeowners.
We developed our Silver Grey Granite Setts Mixed Size Project Pack around these practical characteristics. Instead of using identical blocks throughout the driveway, the pack combines three lengths with a common 150 mm width.
| Granite Sett Size | Per Layer | Per Crate | Net Area per Crate |
|---|---|---|---|
| 350 × 150 × 50 mm | 8 pieces | 64 pieces | 3.36 m² |
| 250 × 150 × 50 mm | 9 pieces | 72 pieces | 2.70 m² |
| 150 × 150 × 50 mm | 9 pieces | 72 pieces | 1.62 m² |
| Total | 26 pieces | 208 pieces | 7.68 m² |
Each wooden crate contains eight layers. Every layer has 26 granite setts covering 0.96 m² of net stone area. A full crate contains 208 pieces and covers 7.68 m² before allowing for joints.
The fixed quantities make it straightforward to plan a mixed-size driveway without ordering three separate products.
Why These Three Sizes Were Selected
The three sizes have different roles within the laying pattern. The 350 mm setts account for 43.75% of the total stone area, providing longer sections that can reduce the number of pieces required across larger areas.
The 250 mm setts represent approximately 35.16% of the pack area, providing an intermediate length between the larger rectangular pieces and the smaller square stones.
The 150 mm square setts account for approximately 21.09% of the area. They help vary the positioning of end joints and prevent the pattern from becoming too repetitive.
This balance between longer and shorter pieces gives installers enough variation to create staggered layouts while retaining a consistent course width.
Why the 150 mm Width Works Well for Mixed Size Block Paving
The common 150 mm width is one of the most useful features of this pack. All three sizes can be laid in parallel courses without constantly changing the width of each course.
The 250 mm and 350 mm lengths cover more ground per piece than the 150 mm square setts. This can reduce the number of individual pieces required for a given area compared with using only small square blocks. The shorter pieces then provide flexibility for changing the bond and breaking up repetitive joints.
Installers still need to plan the laying pattern, particularly around corners, drainage channels and driveway edges. However, combining three lengths of the same width gives useful flexibility without the additional complexity of mixing different course widths.
A Staggered Pattern with a Natural Appearance
A driveway laid entirely with one rectangular size can look quite repetitive. Mixed sizes change that appearance.
The 350 mm stones introduce longer sections, the 250 mm stones provide the intermediate lengths, and the 150 mm square pieces help vary the positioning of the joints.
The finished driveway has a recognisable laying pattern but does not look mechanically repetitive. This slightly irregular arrangement is particularly effective with natural granite, where the mineral grains and colour variations already give each piece its own appearance.
The result is a driveway that looks organised without looking uniform.
How Staggered Joints Help Stabilise Granite Sett Paving
One reason for using different lengths is to avoid continuous cross-joints running through several adjacent courses.
By alternating the 350 mm, 250 mm and 150 mm setts, installers can arrange the stones so that the end joints in one course do not line up with those in the next.
This staggered arrangement helps reduce continuous joint lines and allows neighbouring paving units to contribute to the overall restraint of the surface.
However, the laying pattern alone does not prevent movement. Proper lateral restraint depends on several factors working together:
- A stable, correctly compacted supporting construction.
- A suitable full mortar bedding system.
- Strong adhesion between the granite and mortar bed.
- Properly filled and supported paving joints.
- Secure edge restraints around the driveway.
These details are especially important where vehicles turn, brake or accelerate, as tyre forces can place substantial horizontal loads on the paving.
Installation advice: When laying mixed size granite setts, stagger the end joints between adjacent courses rather than allowing continuous cross-joints to develop. As a practical setting-out guide, aim for joint offsets of at least 50 mm where the pattern allows. Avoid repeatedly placing the 150 mm square setts in identical positions across neighbouring courses. This helps produce a balanced, less repetitive layout while improving the interlocking arrangement of the paving. A suitable mortar bed, properly filled joints and secure edge restraints remain essential for driveway stability.
Granite Setts vs Concrete Block Paving for UK Driveways
Both materials can provide a durable driveway when the supporting construction is correctly designed. The main differences are the material, surface finish, appearance and installation requirements.
| Feature | Silver Grey Granite Setts | Conventional Concrete Block Paving |
|---|---|---|
| Material | Natural granite | Manufactured concrete |
| Shape | Three mixed sizes, 150 mm common width | Typically standardised rectangular or shaped blocks |
| Thickness | 50 mm nominal | Common domestic blocks are often 50–60 mm, depending on product |
| Surface | Sawn and flamed granite | Manufactured textured or smooth finishes |
| Appearance | Natural mineral grains and stone colour variation | Manufactured colours and textures |
| Laying Pattern | Mixed lengths with staggered joints | Running bond, herringbone and other patterns |
| Installation | Rigid full mortar bed recommended for this pack | Often laid as a flexible system on compacted granular bedding |
| Jointing | Suitable jointing compound for the designed rigid system | Usually kiln-dried jointing sand in conventional flexible construction |
| Maintenance | Depends on stone treatment, joints and installation | Depends on concrete quality, joints and installation |
Concrete block paving remains a practical and established driveway material. Our mixed size granite pack offers a natural stone alternative for customers who prefer the appearance of granite while retaining a familiar rectangular paving layout.
The two systems should not be installed interchangeably without considering their different bedding and jointing requirements.
How to Prepare a Rigid Base for 50 mm Granite Driveway Setts
Good granite will not compensate for a poorly constructed driveway base. If the supporting layers settle or move, the finished paving can develop loose stones, failed joints and uneven surfaces.
For this reason, we recommend taking particular care with ground preparation, sub-base compaction, the mortar bed and drainage.
Step 1: Assess and Prepare the Ground
Excavate to the depth required for the complete paving construction. Remove unsuitable material and prepare a stable sub-grade.
Soft spots, made ground and areas with poor bearing capacity need appropriate treatment before the next layer is installed. The construction depth should be determined by the ground conditions, expected traffic and the chosen rigid pavement design.
Step 2: Install MOT Type 1 Sub-Base in Two Layers
For a domestic driveway design specifying 150 mm of compacted MOT Type 1 granular sub-base, a practical method is to construct it in two separate 75 mm compacted layers.
- First layer: Spread MOT Type 1 to an appropriate loose depth, then compact thoroughly using a suitable vibrating plate or roller until the required compacted thickness and density are achieved.
- Second layer: Add the remaining material, level it and compact again to achieve the specified total compacted thickness.
Do not simply place the full depth of loose MOT Type 1 and assume that one pass of a compactor will consolidate the complete layer. Compacting material in separate lifts gives better control of the finished level and compaction throughout the construction.
The loose depth required to achieve a 75 mm compacted layer varies with the aggregate grading, moisture content and compaction equipment. The installer must check the compacted result rather than relying on loose material depth alone.
Important: A 150 mm MOT Type 1 sub-base laid in two compacted 75 mm layers is a recognised example for domestic rigid sett installations, not a universal specification for every driveway. Where a rigid construction requires a concrete roadbase or other bound supporting layer, that layer must also be provided. The sub-base alone does not replace a specified structural concrete base.
Step 3: Construct the Required Supporting Base
The supporting structure must match the intended rigid paving system. Depending on the design, this may include a concrete or cement-bound roadbase over the compacted sub-base.
The roadbase should be sufficiently stable and cured before the mortar bedding is installed. Drainage falls, structural movement joints and edge restraints must also be considered as part of the complete driveway construction.
Step 4: Lay the Granite Setts on a Full Mortar Bed
For our 50 mm sawn granite setts used on domestic driveways, we recommend a properly designed rigid laying system with a full mortar bed. Unlike thicker concrete blocks commonly installed on flexible sand bedding, these natural granite setts benefit from continuous support beneath each stone.
Vehicle tyres create repeated vertical loads as well as horizontal forces during braking, turning and acceleration. Inadequate bedding, unsupported corners or poor adhesion can contribute to movement, debonding and localised cracking. A suitable full mortar bed distributes support across the underside of the setts, while slurry primer improves the bond between the granite and mortar.
The supporting base, mortar specification, bedding thickness and edge restraints must all be appropriate for the expected loads and ground conditions. Do not use isolated mortar spots or dabs beneath driveway setts.
Why Slurry Primer Matters for Low-Absorption Granite
Granite paving stones generally absorbs less water than many porous paving stones. That makes the interface between the stone and mortar particularly important.
If a granite sett is placed directly onto an unsuitable mortar bed without adequate bonding, there is a risk of debonding, especially when the paving is subjected to vehicle loading, moisture and temperature changes.
We recommend FixProMaster FixPrime Slurry Primer as part of a suitable full mortar bedding system.
FixPrime is a polymer-modified cementitious bonding slurry designed to improve adhesion between natural stone or porcelain paving and the mortar bed.
Apply the primer to the clean underside of each granite sett in accordance with the product instructions. The stone should then be bedded while the primer is in the correct application condition, ensuring continuous contact with the mortar.
Good adhesion helps reduce the risk of hollow areas, debonding and movement. However, the primer cannot compensate for a weak base, unsuitable mortar or poor workmanship.
Why High-Quality Epoxy Jointing Compound Is Important
The joints between granite setts are not just an aesthetic detail. They help maintain the spacing between adjacent stones, protect the bedding construction and contribute to the performance of the finished paving.
For a rigidly laid granite driveway, the jointing material must be suitable for the expected wheel loads, joint dimensions and supporting structure.
Our FixProMaster FixJoint Two-Part Epoxy Paving Grout is designed for natural stone, porcelain and concrete paving, including suitable driveway applications.
FixJoint uses a two-part epoxy resin system containing resin and hardener. When correctly mixed and cured, it produces a durable jointing material designed to resist washout, frost exposure, weed growth and normal pressure-washing maintenance.
Why Resin and Hardener Work Together
The resin and hardener react during curing to form the hardened binder within the jointing material. This provides a more durable jointing system than a loose, unbound joint filler when used in a compatible paving construction.
The product is designed for long-term outdoor performance, but its service life still depends on correct mixing, joint preparation, curing and the stability of the underlying paving.
The combination of staggered granite setts, a properly constructed rigid bedding system and suitable epoxy jointing helps produce a more stable finished driveway.
Joint Width and Depth
For this mixed size granite pack, our usual intended joint width is 5–8 mm.
FixJoint specifies a minimum joint width of 5 mm and a minimum joint depth of 20 mm. All joints must be clean, adequately supported and prepared according to the product instructions.
Before use, confirm that the selected jointing compound is compatible with the complete rigid driveway design, including the bedding material, drainage arrangements and expected loads.
Drainage note: FixJoint is described as a permeable jointing compound. However, permeable joints do not make an otherwise impermeable rigid paving construction permeable. The overall drainage design must be appropriate for the site, and surface water must be directed to suitable drainage provisions.
Why Mixed Size Granite Setts Can Improve Laying Efficiency
The use of a common 150 mm width simplifies setting out. Once the first course is established, the installer can alternate the three lengths while keeping the same course width.
The 250 mm and 350 mm pieces also cover more area per stone than small square blocks. This can reduce the number of individual stones handled and positioned, particularly over larger uninterrupted driveway areas.
It does not mean every mixed-size installation is automatically quicker. Complex borders, irregular shapes and cutting requirements can affect labour time.
For straightforward rectangular driveways, however, the combination of consistent widths and varied lengths offers a practical balance between laying efficiency and a more interesting finished pattern.
How Much Area Does One Mixed Size Granite Project Pack Cover?
One complete crate contains 208 granite setts in eight layers, with a total net stone area of 7.68 m².
| Layers | Blocks | Net Stone Area |
|---|---|---|
| 1 | 26 | 0.96 m² |
| 2 | 52 | 1.92 m² |
| 3 | 78 | 2.88 m² |
| 4 | 104 | 3.84 m² |
| 5 | 130 | 4.80 m² |
| 6 | 156 | 5.76 m² |
| 7 | 182 | 6.72 m² |
| 8 | 208 | 7.68 m² |
Our prices are calculated using the actual net stone area of 7.68 m² per crate, excluding paving joints. This ensures customers pay for the granite supplied rather than an estimated laid area.
When the setts are laid with suitable joints, the finished paved area will be greater than the net stone area. The exact coverage depends on joint width, laying pattern and perimeter cuts. For this reason, we recommend calculating the required quantity from the actual driveway dimensions rather than relying on a fixed gross coverage figure.
Cutting and wastage: As a practical ordering guide, allow approximately 10% wastage for straightforward rectangular driveways. For curved edges, angled boundaries or complicated layouts, an allowance of around 12–15% may be more appropriate. These figures are estimates; actual cutting requirements depend on the site layout and installation method.
Our View: A Practical Natural Stone Alternative to Concrete Block Paving
We believe mixed size sawn granite setts offer an excellent option for UK domestic driveways.
The three sizes were selected for practical reasons. Their shared 150 mm width allows straightforward setting out. Their different lengths produce a more varied appearance and make staggered joint layouts easier to achieve.
The flamed granite provides a natural textured surface, while the sawn edges give the finished paving a cleaner, more consistent appearance than traditional hand-split cobbles.
What matters most is the complete installation. A properly compacted supporting base, suitable full mortar bedding, good slurry primer adhesion, appropriate jointing compound and secure edge restraints all contribute to the performance of the driveway.
When these details are handled correctly, the mixed size granite setts can provide a practical, attractive and durable alternative to conventional concrete block paving.
Explore natural stone for your chosen pattern. Browse block paving, granite setts, sandstone cobbles and limestone cobbles. Confirm the available product format before committing to a laying pattern.
Frequently Asked Questions
1. Are mixed size granite setts suitable for domestic driveways?
Yes. Our 50 mm mixed size granite setts can be used for domestic driveways when installed on a properly designed supporting construction with suitable full mortar bedding, jointing and edge restraints. The installation must be appropriate for the intended vehicle loads.
2. What sizes are included in the Silver Grey Granite Setts Project Pack?
The pack contains 350 × 150 × 50 mm, 250 × 150 × 50 mm and 150 × 150 × 50 mm granite setts. Every size has a common width of 150 mm and a nominal thickness of 50 mm.
3. Why are three different lengths used in one paving pack?
The different lengths allow installers to create staggered laying patterns while maintaining consistent 150 mm-wide courses. This produces a varied appearance, reduces continuous joint lines and helps create a properly restrained paving layout when the complete installation is correctly constructed.
4. How many granite setts are supplied per crate?
Each crate contains 208 granite setts in eight layers. There are 64 pieces of 350 × 150 mm, 72 pieces of 250 × 150 mm and 72 pieces of 150 × 150 mm, providing 7.68 m² of net stone area.
5. Should MOT Type 1 be compacted in two layers?
For a driveway design specifying a 150 mm compacted MOT Type 1 sub-base, two separate 75 mm compacted layers are a recognised construction method. Each layer should be thoroughly compacted before adding the next. The required total depth depends on ground conditions, traffic loads and the pavement design.
6. Why use slurry primer when laying granite setts?
Granite is a relatively low-absorption natural stone. A suitable slurry primer, such as FixProMaster FixPrime, helps improve adhesion between the granite underside and a compatible full mortar bed, reducing the risk of debonding when correctly applied.
7. Can FixJoint epoxy grout be used with granite driveway setts?
FixProMaster FixJoint is designed for natural stone paving and suitable driveway applications. It requires a minimum joint width of 5 mm and a minimum joint depth of 20 mm. The complete rigid paving construction must be stable and compatible with the jointing system.
8. Is mixed size granite block paving better than concrete block paving?
Both materials can perform well when correctly installed. Mixed size granite setts offer natural stone colour and texture, a flamed surface and varied laying patterns. Concrete block paving is an established alternative, often installed using a different flexible laying system. The best choice depends on appearance, budget and construction requirements.
