Construction phase support
Lithos are able to help with ground-related problems that sometimes arise during the construction phase of a project.
Almost all residential redevelopment on brownfield land requires placement of a clean soil cover layer in garden and landscaped areas, usually to form a barrier between residents and residual contamination in the ground.
The Council of Mortgage Lenders requires house builders to submit a validation report to the warranty provider confirming the thickness and quality of the soil cover. Lithos provides a proactive service with quick turnaround for validating the placement of soil cover. We employ qualified geoenvironmental engineers who have extensive experience in the sampling of soil cover material to assess suitability. We issue concise validation certificates to gain approval from warranty providers and regulators as efficiently as possible.
Lithos can prepare Gas Protection Strategy and Verification Plans based on findings of the gas risk assessment.
An independent verification regime usually involves inspection of the first plot plus subsequent plots at frequency of 1 in 10, with a minimum of 5 plots to be subject to independent inspection.
Typically, at least two visits are required per plot; one to verify the sub‑floor ventilation and the second to inspect the membrane.
Our engineers are fully conversant with guidance on the design and installation of gas protection measures to all forms of building structure. Current guidance requires at least some degree of independent certification on all developments where gas protection measures are required. The frequency of independent inspections required will vary depending on the level of risk, the type of construction and whether the protection is being installed by a specialist contractor.
Our engineers are fully conversant with the latest guidance on the design and installation of gas protection measures to all forms of building structure.
Typically, inspections are required at two key stages during construction:
- Creation of the sub-floor void
- Placement of the gas resistant membrane
Validation certificates, verifying that the required protective measures have been installed correctly, are issued as development proceeds to enable ‘finalling’ of plots under the CML initiative.
We are able to attend site at short notice to sample stockpiles, schedule appropriate testing, and provide advice with respect to waste classification or suitability for transfer to other development sites (see Materials Management Plans).
Our qualified geotechnical engineers can visit site to inspect and advise on a variety of issues including: suitable founding strata; foundation depths; highway formation etc.
Post-construction Lithos can provide advice relating to geotechnical failure for issues such as: general site subsidence; collapsed mine workings; and building subsidence.
Whilst each situation requires a bespoke approach, concise engineering reports are typically issued that provide an opinion on the cause of the problem, its severity and potential solutions.
Where required, Lithos can undertake ground monitoring to gain data on a specific problem, and can assist the Structural Engineer with the engineering design of the remedial solution.
We are experienced and highly competent at undertaking the review of existing data (including previous site investigation reports), providing a technical commentary and highlighting key ground-related issues that require pre-tender consideration. We are always on hand to provide telephone support and answer e-mailed queries during the tender period, and can attend meetings as required.
