Renovating a Mid-Terrace on the Northside: Month Six Update

Six months in and the house is still standing. That is honestly the best thing we can say about February. The plasterers finished the back bedroom last week, the new windows are in on the upper floor, and there is a functioning bathroom for the first time since October. Progress, of a sort.

For anyone just finding this, we picked up a pre-1960s mid-terrace on the Northside last summer. Two up, two down with a return, the kind of house that was built to last and has done exactly that, while accumulating about sixty years of well-meaning bodge jobs along the way. We knew it needed work. We did not fully grasp what that meant until we started pulling things apart.

The Damp That Wasn't Where We Thought

The survey flagged rising damp in the front reception room. We budgeted for it, got a specialist in early, and were feeling fairly organised about the whole thing. What the survey did not catch, because it was hidden behind a false wall somebody had put up in the 1980s, was a second area of penetrating damp running down the party wall on the eastern side. Different problem entirely, different cause, different fix.

Rising damp comes up from the ground, usually because the damp proof course has failed or was never there to begin with in an older house. Penetrating damp comes in from outside, often through defective pointing, cracked render, or blocked guttering overhead. Treating one will not sort the other, and if you diagnose the wrong one you can spend a lot of money achieving nothing.

In our case the penetrating damp on the party wall was being fed by a gutter on the neighbouring side that had been partially blocked for years. Water was sitting against the wall and working its way through the old brick. The fix on our side involved re-rendering that section internally with a sand and cement mix before replastering, but the root cause was the gutter, which the neighbour sorted out once we explained the situation. They had no idea. These things happen in terraces.

The practical lesson here is simple: do not assume damp is one thing. Get someone to look at it properly before you start treating walls, because the treatments for rising and penetrating damp are not interchangeable.

The Chimney Situation

This house has three chimney stacks serving five fireplaces. Two of the fireplaces had been blocked off at some point, which is not unusual. What is unusual is how they were blocked off: someone had stuffed the openings with whatever came to hand, including what appeared to be sections of old carpet and, in the back bedroom, a bin bag held in place with expanding foam. We are choosing not to think too hard about when that decision was made.

The problem with blocking a chimney badly is that you get moisture. A chimney that is sealed at the bottom but open at the top acts like a funnel. Rain and condensation come down, hit the blockage, and have nowhere to go. Over time you get staining, spalling brickwork, and the kind of cold damp smell that gets into everything. All three of the affected flues showed some degree of this.

We had a sweep in to clear and inspect all five flues before we did anything else. Two of them we are reinstating as working fireplaces, fitting stoves. The other three are being properly capped at the stack with vented terminals that keep the rain out but allow the flue to breathe. If you are blocking a chimney, that is the way to do it. A solid cap with no ventilation is almost as bad as the bin bag method.

One of the stacks also had a crack in the flaunching, the mortar that seals the base of the pots to the stack. That had to be re-done before winter, and given how exposed these Northside terraces can be to the weather off the harbour, we were glad we caught it when we did.

What Nobody Tells You About Mid-Terrace Work

Working on a mid-terrace is a different thing to working on a semi-detached or a detached house. You share walls with two neighbours. Any significant structural work involves a party wall notice, which in Ireland is covered under planning regulations and building control rather than the specific Party Wall Act that applies in Britain, but you still need to inform your neighbours and document the condition of shared walls before work begins. We did this and it saved some awkwardness later when a small crack appeared in next door's plaster after we had some internal walls removed. We had photos showing the crack was pre-existing.

Access is also tighter. Getting a skip in, managing deliveries, working around people's cars on the street, all of it takes more coordination than you expect. Our neighbours on both sides have been patient and we are genuinely grateful for that.

Month seven starts next week. The kitchen is being stripped and we have already found one surprise behind the units. There is always one more surprise.