Specialist excavation · Central London
Careful work. Confined spaces.
Ground worth protecting.
Air excavation and impact moling, with compact compressors for narrow passages, garden gates and sites where access demands a different approach.
Illustrative cutaway · not to scale
Roots revealed, intact.
Soil is removed; the root structure stays in place.
Air excavation reveals roots by progressively removing the surrounding soil.
01 Equipment that fits
02 Ground carefully assessed
03 Protection planned in
The London access problem
A tight side passage shouldn’t be the end of the conversation.
London’s courtyards, garden squares and historic properties demand careful work in confined spaces. Our fleet includes compact, single-tool compressors alongside larger equipment, so we can match the air supply and access arrangements to your project.
Where a road-towable unit cannot enter, our smaller equipment can open up practical options. We check the full route: gate widths, corners, steps and the working area beyond.
Tell us about your access
Airflow, tool demand and access checked together. Final equipment selection is specific to your job.
Three ways to work with the ground
Reveal the roots. Pass beneath the paving. Open up compacted soil. See how each method works, then explore the right approach for your site.
01AIRTOOLS SERVICE
Roots revealed, intact.
Reveal the roots. Respect what stays.
Air spades and lances loosen and remove soil around roots and buried services, reducing reliance on cutting or striking tools. Compact compressors help us reach confined London sites.
Explore air excavation02AIRTOOLS SERVICE
Across, without an open trench.
Connect below. Preserve above.
A pneumatic mole creates a straight route for pipes or ducts between two access pits. On suitable ground, paving and landscaping can stay in place above the route.
Explore impact moling03SPECIALIST REFERRAL
New pathways through the soil.
Open the soil. Create new pathways.
A first air pulse opens fissures in compacted soil; a second introduces treatment material. We connect you with an independent specialist to assess suitability and deliver soil decompaction.
Explore soil careTree protection, made visible
Understand the ground before you disturb it. Explore the roots, the protection area and the extra care needed near existing infrastructure.
Schematic root system. Depth and spread vary.
01 / ABOVE & BELOW GROUND
The drip line follows the outer edge of the canopy. Roots often extend beyond it, with much of the root system in the upper 600 mm of soil.
A pruned crown does not mean a small root system. Neither the drip line nor an RPA boundary marks where every root ends.
Regular single stem, measured at 1.5 m. Other stem forms need a different measurement method.
0.60 m × 12 = 7.20 m
The standard calculation is capped at approximately 707 m² (15 m radius).
Prohibited1 m from the trunk
Precautionary4 × 1.885 m = 7.54 m
Illustrative explanation · not a tree survey or permission to excavate.
Read the zones together
BS 5837 informs development design; NJUG / Street Works UK addresses utility works. One does not cancel the other.
| Framework | Starting point | What it means on site |
|---|---|---|
| BS 5837:2012 | Stem-based RPA, then assessed against the site. | Plan protection, access and any justified works with the project arboriculturist. |
| SWUK prohibited zone | 1 m from the trunk. | No excavation without full arboricultural consultation; no storage. Mechanical open trenching is prohibited. |
| SWUK precautionary zone | 4 × stem girth. | Agree the method. The 2026 handout excludes mechanical excavation other than vacuum excavation. |
| Outside the SWUK zone | Called “permitted” in the guidance. | Continue cautiously and protect roots. This is not a guarantee of root-free ground. |
For ancient and veteran trees, Natural England and the Forestry Commission recommend a buffer of at least 15 × stem diameter, or 5 m beyond the canopy if larger. Do not apply the ordinary 15 m calculation cap to that separate advice.
In England, TPO protection includes roots. Conservation-area notifications, planning conditions and applicable exceptions also need checking. Standards and industry guidance do not replace consent or the agreed tree protection plan.
Air excavation can help investigate roots; it does not itself authorise work in a protected area. A suitable method, root care and supervision remain part of the job.
Planning work near established trees?
Let’s start with the site and its constraints.
Grounded in garden-square experience
As part of London Infrastructure Solutions, airtools.london shares GardenSqua.re’s practical understanding of communal gardens, mature trees and sensitive infrastructure.
That perspective shapes how we approach your site, from the gate we enter through to the ground we leave behind.
Explore GardenSqua.re
For garden committees, estate managers, homeowners, arboricultural consultants and contractors.
Central London focus.
Site-specific planning.
Practical equipment choices.
From enquiry to excavation
Choosing the method comes after understanding the ground.
Share the postcode, proposed works, clear access width and any plans or tree constraints.
We consider access, ground conditions, known services and the need for further investigation.
Agree the method, equipment, protection measures and scope before work starts.
Carry out the agreed work. For soil decompaction, your independent specialist manages delivery.
A practical next step
A narrow gate? Established trees? Services beneath your path? Tell us what you need to achieve and what makes the site challenging.
Useful details include the clear gate width, steps, tight turns and any tree protection requirements.
020 7112 9118 ↗Central London · Homes, gardens & estates