tingle

A tingle is a mechanical device clamped to the middle section of a long guide line, string line, or chalk line to prevent it from sagging under its own weight or wind load. It sits perpendicular to the line and anchors it to a fixed point, most commonly the scaffold, a temporary support structure, or a pre-positioned stake. This allows masons, bricklayers, and concrete finishers to maintain a true, level reference line across spans that would otherwise droop noticeably.

The device consists of a simple metal bracket or clamp, usually cast iron or steel, with a vertical stem or post. The bracket grips the line firmly between two surfaces, often with a tightening screw or wedge. The vertical stem is then secured to whatever anchor point is available. On masonry work, the tingle is particularly common when laying courses over spans of 10 metres or more, where even a tight line will sag enough to cause visible deviation in the finished work.

The simplest form is a single-post tingle with a U-shaped clamp that holds the line and a base or stem for anchoring. Some versions have adjustable height screws to fine-tune the line position. On very long runs, two or more tingles may be used to support the line at multiple points. The vertical element of a tingle is often a wooden post, steel rod, or chain that runs down to a stable base or weight on the ground. The effectiveness depends entirely on how rigidly the tingle itself is anchored; a loose or wobbly attachment defeats the purpose.

Wind and temperature changes can still affect even a tingle-supported line. Masons often check the line visually before laying every course and adjust the tingle if necessary. The clamp or bracket must grip the line tightly enough not to slip, but clamping too hard can damage the line, especially if it is a chalk line made of cotton or synthetic fibre. Steel lines or wire are more forgiving but less common in traditional masonry.

The term itself reflects practical naming: the tingle is a small, subsidiary fixture that "tingles" or lightly touches the line to hold it, rather than being a primary structural element. It appears in British and Commonwealth construction practice more than in North American work, where alternative terms such as "mid-span support" or "sag corrector" are occasionally used, though tingle remains the standard trade term in the UK and Ireland.