Question 1

Which cracks in walls are serious and which are normal?

Accepted Answer

Most cracks in a house are cosmetic. A small number indicate structural movement, and the difference lies in width, shape, location and whether the crack is changing over time — not in how alarming it looks.

Normal, low-concern cracks are typically hairline to around 1mm wide, straight, and appear where materials meet or shrink: along the joint between ceiling and wall, around door and window frames, along plasterboard seams, or in fresh plaster as it dries. New-build and newly extended properties settle for the first couple of years and produce plenty of these. They are filled and painted over, and if they reopen slightly with the seasons, flexible filler or caulk is the answer.

Cracks that warrant a professional opinion have a different character. Watch for cracks wider than about 5mm, cracks that are wider at one end than the other, and diagonal cracks running through brickwork or plaster at roughly 45 degrees — particularly ones that step along the mortar joints outside. Cracks that appear on both the inside and outside of the same wall, cracks around a bay window or an extension junction, and any crack accompanied by doors or windows that have started sticking are all worth investigating.

The most useful diagnostic is time. Fill or mark the crack, photograph it with a ruler alongside, and check it monthly. A crack that stays exactly as it was is far less concerning than a narrow one that is visibly widening.

If the signs point toward movement, the right professional is a chartered structural engineer or building surveyor rather than a subsidence contractor, whose interest lies in recommending work. Your buildings insurer should also be notified before any investigation begins.

Question 2

Why does my house make cracking noises at night?

Accepted Answer

Almost always thermal movement — building materials expanding and contracting as temperature changes, with the sounds concentrated in the evening because that is when the temperature is falling

Question 3

What is the difference between cavity wall and solid wall insulation?

Accepted Answer

The difference is what kind of wall you have, which determines both the method and the cost — and getting the diagnosis wrong is expensive. Which do you have? Homes built roughly from the 1920s

Question 4

How do I fill and sand a wall properly before painting?

Accepted Answer

The finish you get is decided almost entirely at this stage, and the two mistakes that ruin it are filling in one thick pass and sanding while impatient. Prepare the hole first. Scrape out any loose

Question 5

What are the signs that my roof needs repair or replacement?

Accepted Answer

Signs that your roof needs repair or replacement include leaks, missing shingles, granule loss, sagging, mold, and the roof's age. Regular inspections are essential.

Question 6

How do you build a stud wall?

Accepted Answer

A timber or metal frame fixed between floor and ceiling, clad with plasterboard — straightforward in principle, and with several details that separate a solid wall from one that flexes and cracks.

Question 7

How do I tell rising damp from condensation and penetrating damp?

Accepted Answer

The three have completely different causes and completely different fixes, and misdiagnosis is expensive — most damp diagnosed and treated as rising damp is actually one of the other two.

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