Dot-and-Dab, Battens or an Independent Frame

Adhesive placed in patches leaves a void subdivided and partly closed by the adhesive itself. Battens leave a void divided into vertical or horizontal channels. An independent frame leaves an open, continuous space. Each of those geometries behaves differently when air, moisture or sound reaches it.

None of them can be changed once the boards are on, which is why this is treated as a single decision rather than a preference that can be revisited.

Whether the lining touches the base wall is what connects the support method to the wall's condition. A bonded lining shares the wall's temperature and its moisture; a lining held clear does not, and the space between becomes an environment of its own.

Which of these suits a given wall depends on the construction, the exposure and the internal climate, and is assessed by a qualified professional rather than chosen from a board's description.

Bonding adhesive is a fixing material rather than a coating. The depth of adhesive varies across the wall to take up the irregularity behind it, which is precisely why the result is a lining with a void of a depth nobody planned, rather than a board sitting tight against the masonry.

Adhesion depends entirely on the state of the wall face, so old paint, dust or loose material changes what is possible. It is also not a levelling coat, and using it to fill a hollow rather than to hold a board is a misuse of the material.

A timber batten and a folded metal furring channel occupy the same position and in many linings either could be used. The honest difference is form rather than purpose: a batten is solid timber that can be cut, notched, packed, planed and fixed into anywhere along its length; a channel is a folded profile that can do none of those.

What each can accommodate follows from that. A screw driven through the finished lining meets thin metal in one case and solid material in the other, and timber held against a wall that can become damp sits somewhere it cannot be seen.

A frame standing clear of the wall gives an open void and moves every load off the base wall. Where the purpose is acoustic the rule hardens: an ordinary independent-frame lining is still tied back to the wall for stability, while a lining built to be decoupled is self-supporting and nothing crosses the gap at all.

A single restraint fixing, a service clip or a skirting spanning the cavity converts one into the other. Existing walls are rarely straight, so a free-standing frame wanders in and out of the gap along its length, and deciding what the clearance has to achieve at its tightest point is part of the design.

A shelf screwed to a bonded lining loads the adhesive and the wall behind it; the same shelf on a framed lining loads the frame; on a battened lining it loads whichever batten it happens to catch. The finished face announces none of this.

Anything later fixed through the lining can only be fixed where a batten, a channel or a stud is, and that is decided before the lining goes on. A record of the support pattern is what makes the wall usable later, and a wall that sounds hollow is not necessarily failing — nobody can tell the difference from the room side.

Each support method takes a different amount of room, and all of them move the wall face inward. Skirtings, architraves, sockets, radiator brackets and window boards all move outwards by the thickness of the lining and whatever holds it off.

Where a lined wall meets a plastered or framed one, the junction is a change of construction and a likely crack line, so the transitions are worth drawing rather than discovering.