Retaining walls are a necessary part of many construction projects but traditional methods of making level changes are often un-inspiring in appearance and design and can be time-consuming to build. The use of segmental retaining walls (SRWs), breaks from these constraints offering good design flexibility, attractive appearance and both rapid and economical construction.
Here are my Top 10 tips to ensure your retaining wall will be planned, designed and constructed properly and still performing as intended, well into the next century...
1. Understand your site
Gathering good information about on-site soils, drainage, levels and locations of utility services is the best place to start. If the wall is to be more than a metre in height, it will need to be designed by a qualified engineer who will insist on having access to this type of information
2. Get good advice
SRW manufacturers can introduce you to specialist engineers who are experienced in designing with their products. Not only can they produce calculations that demonstrate the wall will perform as required but they can also offer advice that will enable the wall to be planned and built in the most cost-effective manner
3. Photograph the site
Site plans are great but photographs will tell a designer far more. Perhaps the wall might need to be close to an existing building – SRWs are available in many colours which can tone-in with surrounding structures. Photographs can identify other considerations which might be important in the construction project – access problems, a nearby tree or overhead power or telephone cables, for instance.
4. Free your imagination
Conventional wall building methods can be inflexible, resulting in hard, angular structures that sit uncomfortably in the landscape. SRWs are the opposite. Sweeping curves, changes in level, steps and terraces are easy to create – in most cases, no matter how creative the sketch plan, with SRWs, ideas can readily be built just the way they were imagined.
5. Incorporate terraces
Changes in levels break up the face of a large wall. They create attractive and functional intermediate platforms where planting or landscape features can be included. Terraced SRWs have the additional benefit that they allow more light to fall below them than taller walls.
6. Consider the appearance of the wall
Colours of the masonry blocks are important but so are face textures. The clean lines of straight split masonry are ideal for contemporary surroundings but SRWs are also available with softer, more rounded split face textures which are ideal for traditional environments. Consider also the size of the chosen block for the wall – small blocks in taller walls look good but take longer to build; larger blocks in shorter walls will improve the construction speed but can look bulky in some situations.
7. Use experienced people to build the wall
Whilst building SRWs uses skills that can easily be acquired by general contractors, it’s still a good idea to opt for experience if you can. SRWs are generally very quick and straight-forward to build – an experienced contractor will know this and that will reflect in his price for the project! If the chosen contractor hasn’t used these materials before, arrange for the SRW manufacturer to train the team.
8. Plan the build….and build the plan!
Order all the components for the wall and maintain a clean area to store materials where possible. Make sure that the construction team have received training in the proper installation techniques – SRW manufacturers can provide this information and even help with initial training on-site to ensure proper and safe working practices
9. Understand the construction drawings
A good scheme engineer will provide cross section drawings that show exactly how the wall is to be built. Taller walls will probably be reinforced with a geogrid material and the section will show the lengths and elevations of this reinforcement material in the wall. Of course, if the wall has changes in level, there will often be more than one cross section and it is vital to ensure that the project is properly set-out according to these sections and any accompanying drawing.
Above all, don’t deviate from the plan and if there is any need for design changes, consult the engineer first!
10. Attention to detail
Because they are so quick and simple to build, the most important aspect of the building of SRWs is attention to detail.
Work safely – take care to use appropriate safety equipment when cutting or splitting blocks and keep a tidy work area to avoid trips and falls. Maintain line and level – use string lines and ensure that the wall units are levelled front to back as well as side to side – this is especially important for the first course of blockwork.
Because SRWs are dry-built, if there is an error, it is easy to up-lift and re-lay a course of blocks. This way, errors at the beginning of the project can easily be rectified. Ensure that the wall is properly drained – the cross section drawings will show where the wall needs drainage Backfill with free draining material and compact it properly – the engineer who designed the project will be able to advise on what measures are necessary.
Finish the wall properly – use a capping course of blocks (most SRW manufacturers have purpose designed units for this purpose) to give the wall a finished appearance. Also, grade the soil behind the structure so as to drain water away from the face of the wall. Experience gained from thousands of successful SRW projects has shown that observing these ten tips is a great start towards ensuring a successful, cost-effective and visually appealing retaining wall project.
Retaining walls are a necessary part of many construction projects but traditional methods of making level changes are often un-inspiring in appearance and design and can be time-consuming to build. The use of segmental retaining walls (SRWs), breaks from these constraints offering good design flexibility, attractive appearance and both rapid and economical construction.
Here are my Top 10 tips to ensure your retaining wall will be planned, designed and constructed properly and still performing as intended, well into the next century...
1. Understand your site
Gathering good information about on-site soils, drainage, levels and locations of utility services is the best place to start. If the wall is to be more than a metre in height, it will need to be designed by a qualified engineer who will insist on having access to this type of information
2. Get good advice
SRW manufacturers can introduce you to specialist engineers who are experienced in designing with their products. Not only can they produce calculations that demonstrate the wall will perform as required but they can also offer advice that will enable the wall to be planned and built in the most cost-effective manner
3. Photograph the site
Site plans are great but photographs will tell a designer far more. Perhaps the wall might need to be close to an existing building – SRWs are available in many colours which can tone-in with surrounding structures. Photographs can identify other considerations which might be important in the construction project – access problems, a nearby tree or overhead power or telephone cables, for instance.
4. Free your imagination
Conventional wall building methods can be inflexible, resulting in hard, angular structures that sit uncomfortably in the landscape. SRWs are the opposite. Sweeping curves, changes in level, steps and terraces are easy to create – in most cases, no matter how creative the sketch plan, with SRWs, ideas can readily be built just the way they were imagined.
5. Incorporate terraces
Changes in levels break up the face of a large wall. They create attractive and functional intermediate platforms where planting or landscape features can be included. Terraced SRWs have the additional benefit that they allow more light to fall below them than taller walls.
6. Consider the appearance of the wall
Colours of the masonry blocks are important but so are face textures. The clean lines of straight split masonry are ideal for contemporary surroundings but SRWs are also available with softer, more rounded split face textures which are ideal for traditional environments. Consider also the size of the chosen block for the wall – small blocks in taller walls look good but take longer to build; larger blocks in shorter walls will improve the construction speed but can look bulky in some situations.
7. Use experienced people to build the wall
Whilst building SRWs uses skills that can easily be acquired by general contractors, it’s still a good idea to opt for experience if you can. SRWs are generally very quick and straight-forward to build – an experienced contractor will know this and that will reflect in his price for the project! If the chosen contractor hasn’t used these materials before, arrange for the SRW manufacturer to train the team.
8. Plan the build….and build the plan!
Order all the components for the wall and maintain a clean area to store materials where possible. Make sure that the construction team have received training in the proper installation techniques – SRW manufacturers can provide this information and even help with initial training on-site to ensure proper and safe working practices
9. Understand the construction drawings
A good scheme engineer will provide cross section drawings that show exactly how the wall is to be built. Taller walls will probably be reinforced with a geogrid material and the section will show the lengths and elevations of this reinforcement material in the wall. Of course, if the wall has changes in level, there will often be more than one cross section and it is vital to ensure that the project is properly set-out according to these sections and any accompanying drawing.
Above all, don’t deviate from the plan and if there is any need for design changes, consult the engineer first!
10. Attention to detail
Because they are so quick and simple to build, the most important aspect of the building of SRWs is attention to detail.
Work safely – take care to use appropriate safety equipment when cutting or splitting blocks and keep a tidy work area to avoid trips and falls. Maintain line and level – use string lines and ensure that the wall units are levelled front to back as well as side to side – this is especially important for the first course of blockwork.
Because SRWs are dry-built, if there is an error, it is easy to up-lift and re-lay a course of blocks. This way, errors at the beginning of the project can easily be rectified. Ensure that the wall is properly drained – the cross section drawings will show where the wall needs drainage Backfill with free draining material and compact it properly – the engineer who designed the project will be able to advise on what measures are necessary.
Finish the wall properly – use a capping course of blocks (most SRW manufacturers have purpose designed units for this purpose) to give the wall a finished appearance. Also, grade the soil behind the structure so as to drain water away from the face of the wall. Experience gained from thousands of successful SRW projects has shown that observing these ten tips is a great start towards ensuring a successful, cost-effective and visually appealing retaining wall project.
