What is Trial Pit

What is a Trial Pit?

In this property blog, we will be discussing trial pits, what they are, and when they are applicable to the Party Wall etc. Act 1996.

I will be discussing trial pit requirements from a Party Wall surveying procedures stance. A trial pit is usually required when a building owner’s, planned construction works, requires forming a flank wall or new structure up to, or in close proximity to an existing adjoining owner’s structure.

Here at Icon Surveyors, we specialize in Party Wall surveying, trial pits are a common scenario, they are usually required if, a property owner known as the building owner, plans to undertake a rear extension up to the boundary line at his semi-detached property, and the neighbouring owner known as the adjoining owner has an existing extension with the flank wall 100mm from the boundary.

It is common to find older structure foundations, built in a way, whereby considerations are taken into account for modern standards, you will even frequently find foundations crossing boundary lines.

Wat is a Trial Hole?

A trial hole / trial pit, is small controlled hole, usually no bigger than a m2, this hole is commonly dug by one contractor in a safe manner and by hand, i.e. without use of machinery. The depth of the hole will be to the bottom of the neighbouring owner’s foundations, thus confirming the exact profile of the foundation. Once armed with the required information the building owners Architect or Structural Engineer, can then provide the relevant foundation detail, ensuring that the neighbours structure will not be compromised.

We believe a trial pit is worth undertaking as it fully informs both contractors and design teams, of what sits beneath ground, in-turn allowing them to provide their structural details and designs with this being accounted for, thus being both time and cost-effective in ensuring damage risk is as low as it can possibly be.

It is very common for Party Wall Surveyors to request a trial pit is undertaken, as this will ensure he is doing everything he can to make sure his appointed owner's property is at the lowest risk it can be. With this in mind, make sure you undertake your trail hole early in your build, ensuring you are not caught out at a later stage, costing both time and funds to your planned build.

If you would like to discuss the party wall surveying procedures in relation to proposed works, give our highly qualified team of Party Wall Experts a call. Here at Icon Surveyors, we are always happy to assist in any way possible.