How to deliver optimum quality each and every time
As one of London’s longest established premium architecture practices, LA have a proud reputation for achieving the highest quality of finish in our projects. It doesn’t matter how great the design is if it is poorly executed on site. We maintain a quality control role throughout the site phase of all of our projects, regularly visiting site and inspecting the conformance of the works with the design, and the quality of workmanship. But it is impossible to avoid minor defects so it is vital that these are picked up and rectified in their entirety. This process is what is known as “snagging”. LA Associate, Miruna Stroe explains more:
What is Snagging?
Snagging is an argotic term used across the construction industry to describe a specific type of inspection carried out in the build-up to the awarding of practical completion for a project, or section of a project, in order to identify any minor defects or omissions that are not in accordance with the contract that need to be rectified by the Contractor. This covers both design and workmanship. While a thorough inspection before handover is always a requirement of a building contract, it is especially important in the high-end projects that we work on, where the specified quality standards are usually much higher than other types of project, and tolerances much smaller.
Although the snagging list or report is not an established contractual document, it is normally a prerequisite of the Contract Administrator issuing a certificate of practical completion. Any defects recorded should be resolved by the contractor before they leave site and the rectification period begins.
Who carries out Snagging?
Snagging is a collaborative process: before anyone from the design team inspects “complete” work it is essential that, firstly, the responsible subcontractor carries out their own snagging and making good and, secondly, the Main Contractor does too (these are often combined into a single round of inspections for speed).
Only when the contractor is satisfied with the quality of the works will they invite representatives from the design team to carry out their own inspection. This is generally done by the Project Architect, Contract Administrator, Surveyor or an Employer's Agent, who is tasked with producing a comprehensive Snagging Report. We, as architects, are best placed to judge any deviations from the contract design (be that details, finishes, specifications etc) and the quality of workmanship because, after all, we are its designers! And, as Lead Designer, we also hold ourselves to be the warrantors of the quality of our projects throughout their development, especially at completion.
Because it deals with defects and omissions, or any other instances of unacceptable quality, snagging is a process that inevitably can be the source of disagreements between the design team and the Contractor. Therefore, it is essential that the level of detail for snagging is mutually agreed in the contract and that the requirements are properly defined through approved samples. A benchmarking snagging meeting before the final inspections is also advisable. At this, the design team, client representative, Contractor and relevant subcontractors will review the approved control samples and then assess a specific area and agree what would be considered a ‘snag’. When it comes to finishes, the British Standard states that if a snag cannot be seen from 1.5m away then it is not a snag. However, for the high-end projects we work on we always reduce this to no more than one metre, sometimes even less. We can be slightly more lenient in back-of-house areas! The lighting conditions are also an important factor. Wherever possible, snagging should be conducted in natural daylight, not under artificial lighting. If the latter cannot be avoided then it should at least be the actual lighting that will illuminate the finished space, not a temporary lighting installation. It is important to keep referring to the approved control samples, especially when looking at specialist finishes and joinery. When working with natural materials, natural variations need to be considered as well.
Ideally, the design team’s snagging inspections should happen once the works are complete, the site is dust-free and a “sparkle-clean” has been done. However, this seldom happens, due to tight programmes. Usually, areas are offered for inspection as they finish, while in adjacent areas works are still being completed. Provided this is properly managed by the Main Contractor, i.e. rooms are sealed off and no further access is needed by any site operatives, this works well and allows a desnagging team to follow closely behind.
Snagging should not be confused with testing or commissioning inspections, which should be completed separately and witnessed by the MEP Engineer. As an example, the commissioning inspection might note the installed LED strips in joinery as acceptable if they are properly controlled by the Lutron system. Still, the snagging inspection might point out a difference in colour temperature between the 2700K specified and 3000K installed, or that there might be shadows along part of their length.
Methods and technology
There are various ways of organising a snagging report, either by zone/room or by trade. We prefer to take the room-by-room approach. Once in a room, we inspect the quality of all finished surfaces methodically (walls, then ceiling, then floor), the joints between different surfaces or finishes (grout, shadow-gaps, trims), the functionality of all windows, doors, cupboard doors, drawers, etc. We look for scratches, cracks, uneven areas, fraying edges, splinters, overspills of adhesive, etc. All of these can affect the perceived quality of a finished surface. If it’s a kitchen or bathroom, the functionality of all appliances and sanitaryware is tested. Sockets and lighting controls are also checked.
All observations are noted in detail, along with photographic references, and identified on the relevant room drawings (plans or elevations). It is preferable for the responsible trade to be identified in the snagging record so the Main Contractor can efficiently assign desnagging responsibilities. Another helpful practice is to physically mark each snag with a small piece of masking tape, to assist with locating it later. Quick notes can be added on this tape and different coloured tape can be used to differentiate between trades.
The process of carrying out these inspections and preparing the reports is nowadays greatly simplified by using specialist snagging apps. These are a mobile app for creating the reports, taking photos and locating the snags on the drawings all in one place, and provide an online platform for issuing and archiving the published reports. At LA, we use one such app that greatly simplifies the process of producing site reports on the fly. All information is recorded on site (photos, description, trade designation, plan and/or elevation location) and then, back in the office, a PDF report can be generated immediately. Gone are the days of preparing the report taking longer than the actual inspection!
Lees Associates use a specialist snagging app to quickly prepare comprehensive, user-friendly reports
De-snagging
Once the design team’s snagging report has been issued, it will be acknowledged by the Contractor and the remedial works can progress. Occasionally a snag might be contested by the Contractor and/or an alternative solution needs to be identified. Generally, the Contractor will schedule the remedial work and, when that is completed, will invite the “snaggers” back for a final de-snagging inspection to verify that all issues have been closed to the contractual standards. In this instance the app is useful again: each snag location is verified and noted as completed within the app and then a de-snagging report can be issued. Once all remedial works have been confirmed by a de-snagging report, the Contract Administrator can confidently award Practical Completion. Sometimes some defects can not be remedied in a short enough timeframe, in which case a schedule of defects still to be remedied by the Contractor, along with a timeframe for each, will be appended to the PC certificate. Of course, this is best avoided if possible.
The process of snagging to identify all defects within a completed area of work is vital in order to ensure the client receives the quality of finish and execution required in a building contract. As a practice that specialises in cradle-to-grave design supervision and with a proud reputation for achieving the highest quality standards, Lees Associates can be relied upon to work with Contractors to deliver the optimum product every time.