Home-Repair on Easy-DYI

Drying a house after a burst pipe

Wed, 17 Jun 2026 00:01:00 +0200

The dishwasher incident I wrote about recently - two litres of water into the mineral wool, a home dehumidifier, sorted in a day - was, in the grand scheme of water-related home disasters, a rounding error. It did remind me of something considerably less manageable. A different house, about fifteen years ago.

The morning

I woke up hearing running water, somewhere downstairs. I walked down, checked kitchen and bathroom first - both were OK. Then I opened the door to the garage. Ankle deep water.

The water had been running for hours. The bill that arrived later confirmed it - the volume was in the thousands of litres. The whole ground-level utility area was flooded.

I thought I was lucky. The garage and boiler room had relatively thin concrete floors with little insulation, meaning the level was about 15 cm below the rest of the house - which looked dry.

Step one: stop the water

Main stopcock was the obvious first step. Once the water stopped flowing, I could look for the source properly. The burst pipe was behind the boiler - a joint that had let go, probably factory defect, as the house was quite new. Better news: there was an isolation valve for that section of pipework. Once I closed it, the rest of the house had working water while the repair was arranged.

Pumping out

The garage and boiler room needed emptying. I used a garden pump - the kind sold for emptying garden ponds or irrigating with rainwater. It took a while but it worked. While it was running and for the rest of the day, I kept the garage door and the boiler room door fully open: it was a sunny day, reasonable airflow, and I thought that would be enough.

The next morning

The walls around the entire ground floor of the house were damp. Not just near the garage - walls in rooms on the opposite side of the building. I lifted a floor panel well away from the flooded area, and found water sitting under the floor.

What had happened was obvious in retrospect. Thousands of litres don’t just sit where they land. Water finds every gap, every void, and it spreads. The concrete and masonry had absorbed it laterally and it had travelled, slowly and invisibly, throughout the ground floor structure. What looked dry on the surface was sitting on saturated subfloor and wicking moisture up into the walls.

Who you gonna call?

This was not a DIY job. The scale of moisture intrusion, spread across an entire ground floor - floors, walls, subfloor void - needed proper equipment and someone who knew how to use it. I filed an insurance claim and found a professional drying service. This is worth knowing: burst pipe flooding is a standard insurance event, and most household policies cover the drying.

The drying process

The technician arrived with a van full of hardware that looked like it belonged on a factory floor. What followed was a systematic, several-week operation.

First deployment: three large industrial dehumidifiers placed at strategic points around the ground floor, plus high-volume fans to create airflow through the space. These are not the units you buy at a supermarket - commercial drying dehumidifiers extract 50-100 litres per day. He also drilled holes in the base of walls and lifted floor panels to allow trapped moisture to have somewhere to exit.

Follow-up visits: he came back every few days with a moisture meter, took readings at marked points throughout the house, moved equipment as the drying front progressed, and adjusted the setup accordingly. Drying a structure isn’t a static operation - as the moisture distribution changes, the equipment placement needs to follow it.

Infrared heaters: at a later stage, directional infrared heaters were aimed at specific areas where moisture was stubbornly high. Infrared heats the surface and the material directly, accelerating evaporation from those spots without heating the whole room.

The long tail: one dehumidifier stayed for several weeks after the main equipment was collected. Drying masonry and concrete is slow work. The last moisture is the hardest to shift.

The ozone treatment

The final step, once moisture readings were satisfactory throughout: an ozone generator, run through the sealed house for a day while we stayed elsewhere.

There was no visible mould anywhere, but moisture over an extended period creates conditions for fungal and bacterial growth even where it’s not visible. Ozone (O₃) is a highly reactive form of oxygen - three atoms instead of the usual two - that kills mould spores and bacteria.

The useful property of ozone for this application is that it’s unstable. At room temperature, O₃ breaks down naturally into regular O₂ within hours - the half-life is roughly 20 to 50 minutes depending on temperature and humidity. Run an ozone generator for a few hours, then leave the house closed for a few more, and by the time you return there’s no ozone left. Unlike chemical fungicides, which are toxic to humans, require ventilation and still leave some residue, ozone simply reverts to oxygen.

The bill

The electricity consumption for the month was close to our usual yearly usage. The drying service itself was a significant professional fee. Combined: a number I would not have wanted to pay out of pocket.

All of it was covered by the insurance. Most of the devices had built-in energy counters, those that hadn’t were connected through power meters. At the end, we got energy usage report to show to the insurer.

Could you hire the equipment yourself?

Yes. Industrial dehumidifiers, high-volume fans, and ozone generators can all be hired from specialist hire shops. Doing it yourself is cheaper per day than a drying service that includes a technician.

I wouldn’t recommend it for a large flooding event. The hardware is only half of the success. The other half is knowing where to put it, how to identify where moisture has travelled that isn’t visible, when to move to the next phase. The technician on my job clearly had experience with dozens of similar situations.

What I did afterwards

While the drying was in progress, I ordered a few leak detectors. Small battery-powered devices with two electrodes on the base - when water bridges the electrodes it triggers a loud alarm. They cost almost nothing and run for a year or two on a battery. I put them on the floor everywhere a leak seemed likely. They wouldn’t prevent a leak, but would turn it into an easily manageable event.

A thing I considered but didn’t implement was an automatic water shutoff - a leak detector that closes the main valve when triggered. Unlike the alarm, it would work even when nobody’s home.

Drying mineral wool, or how I flooded my underfloor insulation with a dishwasher

Tue, 16 Jun 2026 10:04:00 +0200

Flooring: part 3 of 4

The floor replacement job was going slowly, but surely. With a few boards missing, I had a thought that seemed perfectly reasonable at the time: why not temporarily hook up the dishwasher? Every hour spent washing dishes by hand is an hour not spent on the actual renovation. Solid logic.

The water supply connection was fine. The wastewater connection was supposed to be provisional. Turned out to be a bit too provisional. I did a reasonable thing of being nearby when the dishwasher was on. Dishwashers pump out water at least twice during a standard cycle. The initial rinsing went fine. But when the cycle was nearly finished and the machine began dumping water again, I heard the splashing and made it across the kitchen in time to grab the hose and hold it in place for the rest of the drain.

Quick reaction. Maybe half a litre escaped. Actually, probably closer to two litres. The mineral wool under the open section of floor had a nice wet patch, and I had a new sub-task to deal with.

How bad is it really?

Rockwool (mineral wool) is pretty forgiving when it gets wet. Rockwool holds its structure and can be dried out and reused. But you do have to actually dry it, leaving wet insulation under a floor is a fast track to mould.

How to dry floor insulation

Step 1: pull out the wet batts

Fortunately I already had the floor open, so this part was easy. Rockwool pulls out in sections without much fuss. I took the affected pieces and laid them flat. Not stacked - airflow is what you want. On a sunny day, I would take them outside and they would be dry in an hour. No such luck, they stayed inside.

Step 2: dry the joist bay

Even with the insulation out, the timber underneath was damp. I ran a dehumidifier right next to it and the pile of wet wool. If you don’t have one, they can be hired. Larger versions are used to dry flooded houses. Mine is not an industrial type - just the regular home model that’s useful in rainy autumns of UK and Sweden. Good enough for a small flooding.

Move some air through. I used my shop vacuum - most can work as blowers if you connect the hose to the exhaust port instead of the intake. The air is also warm after going past the 1000W motor, which helps. I used it in short burst, while the dehumidifier was running for hours.

The dehumidifier shows air humidity. I don’t think the meter is accurate, wouldn’t trust the absolute value, but I didn’t need it. Trend is important. For many hours, the number was constant. When it started dropping, I knew I was getting somewhere. A moisture meter would be perfect here - you’re aiming for timber moisture content below around 18–20% before closing up. I don’t have one, so I kept drying until I couldn’t see and feel the moisture and the dehumidifier meter stopped dropping, and then a few hours more.

Step 3: put everything back

Obviously.

What if you can’t reach the insulation?

I got lucky having the floor already open. If the boards are down and you know some water got below them, the best thing would be to get the floor open and remove the mineral wool like I did.

What if it’s not reasonably possible? What goes below is a speculation - haven’t tested it, but that’s what I would do. Get some opening over the affected area - cut a section or at least drill with a hole saw. Blow a lot of air through it for a few days. Check regularly. I would definitely get a moisture meter in that case. It’s cheap. Dealing with the underfloor mould after you installed the floor, cabinets and appliances - isn’t.

Lessons learned

Total time added to the project: about two days of waiting, maybe an hour of actual work. I was lucky I had the dehumidifier.

Rockwool fibres are itchy. Wear gloves. Then wash your hands, because the fibres got through the gloves. Then shower, because somehow they got on your shoulders, legs and perhaps some unmentionable places.

The kitchen is now back to normal - the boards, the panels on top of them and the cabinets. And the dishwasher stands on a droppbricka - a Swedish standard drip tray that channels any leaked water forward where you’ll see it, rather than letting it flow out of sight. Required by the Säker Vatten industry standard and a good idea anyway (there’s one under a fridge too). The wastewater hose is clamped properly.

And the dishes got done during the renovation, which was the whole point - so I’m calling it a qualified success.

Replacing floorboards: necessary, unglamorous, done

Tue, 16 Jun 2026 10:03:00 +0200

Flooring: part 2 of 4

After removing the vinyl floor, I discovered some floorboards in the kitchen needed replacing. Not many, maybe seven or eight. It seemed so basic - after all, that’s just some measuring, sawing, drilling and screwing - but in combination, it was one of the more tedious renovation tasks I’ve done. Most jobs require either precision or working with large and heavy objects, this one needed both.

Know your floor first

My boards are 180 × 60cm, 22mm thick, laid over joists spaced at 60cm centres. This is a common standard in European construction, but check your house rather than assuming. The joist spacing matches the board width.

Boards can be placed both along and across the joists. Check which direction requires less cutting. Important: board edges should land on a joist, not dangle in the air.

Removing the old boards

This was the most time consuming and tedious part of the job.

Cutting the boards out. A plunge saw set to exactly the board depth - 22mm in my case - cuts the board without touching the joists below. In the beginning I didn’t know where the joists where and some exploratory surgery was necessary. More importantly there may be pipes and cables running beneath the floor. A plunge saw you can set to a precise depth is the right tool here.

Getting the boards up. After getting some access, I tried to remove the boards. They were both glued and screwed to the joists. Most screws were easily removed with a drill/driver, or for more stubborn ones - an impact wrench. 2 or 3 snapped (impact wrench means something WILL be removed). I cut them flush using a rotary tool (I don’t know what they were made of, but multitool blade only got its teeth rounded).

The glue, applied by someone who clearly had an infinite supply, was the main task. The sequence that eventually worked: oscillating multitool with a saw blade along the glue joint to break the bond, then a prybar to lever the board up. Sometimes a sabre saw held horizontally if the board couldn’t be convinced to move. Then, once the board was off, a belt sander on the joist tops to remove the remaining residue.

At one point I counted 8 powertools. I didn’t know I even had that many.

Fitting new boards: dry run first

I made a mistake of glueing and screwing the first board. It then turned out I should have started from the other side to fit to the existing boards properly. I removed it (luckily I haven’t used as much glue as the original creator) and learned to lay all the new boards in position without fixing them. Discover problems before the glue is on, not after.

Fixing sequence: apply wood glue (construction adhesive, something flexible rather than rigid - floors move) to the joist tops, lay the board, drill pilot holes through the board and into the joist, then drive the screws. Countersink the pilot holes so the screw heads sit below the surface. Pilot holes are not optional here. Dry timber splits when you drive a screw without one, especially near the board edge over a joist.

The click edge problem

Modern floorboards typically have a click-lock profile on their edges - a tongue and groove system that snaps the boards together and keeps them aligned. This is fine when you’re laying a whole floor from scratch. It becomes a problem when your new boards meet old ones.

My replacement boards clicked together perfectly among themselves, so did the old ones. Where a new board met an existing old board, the profiles didn’t match - different manufacturer, different era. The solution was to cut the profile off the edge that meets the old floor, leaving a flat butt joint. I used my plunge saw again. A butt joint between floorboards is not as strong as a click joint - there’s nothing mechanical holding the two edges together, just the fixing to the joist below. In practice, if both boards are properly fixed to the joist at that point, the joint is stable enough.

Cutting

New boards in need of cut were clamped to my pallet workbench and treated with my trusty plunge saw on a track rail. This gives clean, accurate cuts. Far better than a freehand cut could achieve. I sometimes made small cuts in place, relying on the depth control again.

For complex cuts, I made cardboard templates. Where a board had to fit around a pipe or into an irregular corner, I cut a piece of cardboard to fit the space first, then transferred the shape to the board. I did these cuts using multitool, the plunge saw is only useful for straight lines. Not millimetre accuracy, but I didn’t need it.

There will be dust

Floorboard work generates an unreasonable amount of dust. The belt sanding of joists alone is enough to coat a room; the saws add more. A PM2.5 meter at times showed 400 μg/m3 (WHO recommends to keep it below 5 on average and not exceed 25). I used all the mitigations I could.

Shop vacuum connected to the tools. The plunge saw and the belt sander have dust extraction ports; the vacuum plugged directly into them caught the majority of cutting dust at source. This is the highest-leverage step - stopping the dust before it becomes airborne is much more effective. What it couldn’t catch was still enough to be a problem.

Dust mask throughout. Not just during cutting and sanding, the dust stays airborne for a long time.

Vacuuming everything. At the end of each session and throughout; whenever I saw some accumulation and especially before putting the new floorboard.

Air purifier running in the room. A HEPA purifier needs time to work, leave it running during work and for a few hours afterwards. And don’t forget to vacuum the filter every day. Home purifier wasn’t designed for these conditions, but it works anyway.

One thing I didn’t do well: sealing the workplace from the rest of the house. There was no door to the kitchen, I hang a few plastic sheets on the doorway without bothering to seal them properly (I wanted to move in and out without resealing). The result was what I should have expected: if I could find the way through the sheets, then dust particles - much smaller than me - also could.

The result

This is one of the bigger renovation jobs I’ve ever done, and one I don’t want to repeat for a while. The removal phase specifically - the glue, the prybar, the belt sanding of joists. The fitting phase was more fun, except for fitting new boards to old boards and making the complex shapes (I had to use the well-known approach: measure twice, cut three times).

Having it done by professionals would be a reasonable choice. A DIY job, unpleasant at times, was deeply satisfying when it ended.

Removing old vinyl flooring: a case for a motorised scraper

Tue, 16 Jun 2026 10:02:00 +0200

Flooring: part 1 of 4

There’s a special kind of optimism that comes with removing old floor covering. I pulled back a corner of the old vinyl, saw it peel away reasonably cleanly, and thought: I’ll be done in an hour.

Then I found the glue. Old vinyl flooring is often stuck down with adhesive that had decades to cure into something with the structural integrity of a geological formation. You pull the vinyl - nothing happens, you pull harder - it tears.

This is the story of working through three approaches, two of which were insufficient, before finding the one that actually worked.

A safety note before anything else

If your vinyl flooring was laid before some time in the 1980s (depends on the country), stop before you start attacking it aggressively. Vinyl floor tiles from that era may contain asbestos. Asbestos is RELATIVELY (I can’t emphasise it too much) safe when left untouched, but dangerous when you start cutting it.

If in doubt, send the material for testing. My house was built in the 1990s, well after the total ban on asbestos in Sweden.

Attempt one: hand tools

The classic scraper is the obvious starting point. So is a knife, a pry bar, a cold chisel supported by a hammer. I experimented with a few options, after an hour I removed maybe half a square meter. Heating the glue didn’t help.

That definitely won’t do.

Attempt two: oscillating multitool

Oscillating multitool is great for home renovation - I’m going to write more about it soon. It’s excellent for scraping in general, much faster than a hand scraper and requiring less effort.

But for that kind of job, the blade is too narrow and the tool is too weak. You’re working a strip maybe 50–80mm wide at a time. If I only had one small room, it would take a day. But I had a whole house to do. That would take weeks (I have my day job), probably wear out the tool, plus working with it for more than an hour gets really unpleasant.

It was still the right tool for the doorways, the corners, the bits around pipes - all the places a large machine can’t reach. For the open floor area, I needed something bigger.

The actual solution: the floor scraper machine

The electric floor scraper I got - also called a floor stripper - was essentially an oversized version of my oscillating multitool. A blade was wider and longer, the motor had 1500W compared to 300W of my tool. The weight of the machine and the wheeled base make pressing the blade into the floor easier (not super easy).

The difference in speed is not incremental. It’s transformative. What was an hour of back-breaking labour by multitool (not to mention hand tools) takes five minutes. The machine keeps constant pressure on the blade, works a wide path on every pass.

Depending on your floor material, you still might have a hard time pressing the machine into it. The solution is to cut it into more manageable strips. Usually, a few minutes with a boxcutter. But in one room, I had 2 layers of very heavy vinyl with a cured adhesive between them. It was impossible to press the machine for more than a few centimeters, and cutting with a knife would take ages. I had to use my trusty plunge saw, set to the depth of 5mm. Cutting vinyl is messy even with dust extraction, if you ever have to do it, wear a dust mask.

Rent, don’t buy

An electric floor scraper is expensive and you will use it once, maybe twice in a lifetime. Two sensible options are: rent, or buy second hand and possibly resell. I rented for a weekend, that was enough.