Common problems in London's older housing stock
Much of London's HMO stock is Victorian and Edwardian terraced housing converted into flats or bedsits decades ago, long before current fire separation standards existed, and the problems tend to repeat from house to house across boroughs. Lath-and-plaster ceilings, common on the original upper floors of these properties, don't provide anything like the fire resistance a protected escape route needs and usually have to be overboarded with fire-rated plasterboard or, where they're too far gone, taken down and replaced entirely. Timber floorboards with gaps between joists let fire, smoke and sound travel between storeys far faster than a fire strategy assumes, so we fire-stop these voids as standard wherever we open up a ceiling or floor on an escape route, using intumescent mastic and mineral wool packed between joists rather than just boarding over the gap. Houses converted into three-storey HMOs served by a single staircase are especially exposed, since that stair is the only escape route from the upper floors and every door opening onto it, bedroom doors included, needs to hold back fire for the required time. We often find these doors replaced at some point with standard internal doors that look similar but carry no fire rating, sometimes with the intumescent strips and cold smoke seals missing entirely, which is one of the most common reasons a previously licensed HMO fails at renewal. Ex-council flats and maisonettes converted into HMOs bring a different set of issues. Concrete cross-wall construction limits where new partitions can go structurally, but it usually gives you fire and sound separation between units for free, which isn't the case in a timber-framed Victorian conversion. Single-glazed metal-framed windows original to some 1960s and 1970s blocks can complicate means of escape if a bedroom relies on a window as a secondary exit, and solid concrete floors make alarm cable runs and any new plumbing routes more involved than lifting a timber floor. Solid-wall Victorian and Edwardian houses without a cavity also need rising or penetrating damp addressed before new plasterboard and skim goes up around a fire-separation upgrade, since boarding over a damp wall just traps the moisture behind a new surface and the fire-rated board itself can be compromised by ongoing dampness within a few years. Loft and mansard conversions added to a terrace to create an extra letting room bring their own escape route problems, since a loft bedroom is often the furthest point from the front door and depends entirely on the stair below being properly protected. Where a loft was converted some years ago under permitted development without a fully protected stair, we sometimes need to upgrade doors and linings on every floor below it, not just in the loft itself, to bring the whole escape route up to the standard the additional storey now demands. Cellar or basement conversions used as an extra bedroom raise a related issue: a below-ground room usually needs an independent means of escape, such as a window or hatch to a lightwell, rather than relying solely on the internal stair, and retrofitting that into an existing solid-wall cellar is one of the more involved jobs we take on.