Demolition of metal door frames (concrete)

Every opening is a little different, but in practice the sequence is much the same:

1. Preparing the area. Furniture is moved away and the floor and surroundings are covered. Cutting steel throws sparks that burn through thin plastic sheeting and laminate flooring, so a thicker board, a fire-resistant sheet or heavy cardboard goes under the cutting point. If there is a floating floor next to the frame, it is often taken up near the opening or at least well protected.
2. Taking off the door. The door leaf is lifted off its hinges, and skirting, architrave, the threshold and any tiles that run into the frame are removed.
3. Checking for cables and pipes. There is usually a light switch beside the door, and a cable often runs above it. A detector shows where cables and pipes run, so cutting and chiselling do not damage them.
4. Cutting the frame. An angle grinder is used to cut through the frame, usually in the head and in both jambs, and sometimes near the floor where there may be a spreader bar. Smaller pieces come out more easily and put less strain on the wall.
5. Freeing it from the concrete. The pieces are levered out one by one with a pry bar, and the mortar or concrete around the profile is carefully broken out with a chisel or a small breaker. The fixing lugs are cut off flush with the wall.
6. Cleaning up the opening. Leftover mortar, sharp edges and protruding lugs are removed, and the opening is cleared of dust.
7. Disposing of the waste. The steel can go to a scrap metal dealer or recycling centre. Rubble belongs at a recycling centre or in a skip for construction waste, not in household waste.

How demanding the job is, and so how long it takes, depends on a few things you can judge before work starts:

• How the frame was fixed. If the profile is completely filled with mortar or was cast into the concrete when the building went up, removal is slower than with a frame fixed at only a few points.
• Wall thickness and type. A thick concrete wall is much harder than a masonry partition, and breaking out takes longer.
• Size and shape of the frame. Non-standard, wider or double-door frames mean more cuts and more chiselling.
• Surrounding finishes. Bathroom tiles, floor tiles or a new floor right next to the frame call for slower, more careful work.
• Space and access. In a narrow hallway or a small flat, tools are harder to handle and protecting the surroundings takes longer.
• What comes next. If the opening also needs to be widened, it is no longer just frame removal but alteration of the wall itself (see below).

Taking a frame out of an existing opening does not really alter the wall. It is a different matter if you want to enlarge or move the opening. Concrete walls in blocks of flats are often load-bearing, and widening an opening in them is an alteration to the structure. In that case you need a structural engineer's assessment, and you should check with your local building authority beforehand which approval or notification the local building regulations require. Do not assume that a simple notice will be enough.

In a flat, it is worth telling the building management or owners' association before you start, and keeping to the hours the house rules allow for noisy work. Neighbours also appreciate a short note in the stairwell, because breaking out concrete carries through the whole building.

If you are confident with an angle grinder and you are not going to enlarge the opening, you can do this job yourself. Expect noise, dust and sparks. If you are unsure where cables run, or the work involves altering a load-bearing wall, leave it to professionals.

1. Put on safety goggles or a face shield, a dust mask, ear defenders and sturdy gloves.
2. Switch off the circuit breaker for the light switch next to the door.
3. Lift off the door leaf and remove the trims and the threshold.
4. Cover the floor with a non-combustible sheet and move anything that could catch fire from sparks.
5. Check the position of cables and pipes around the frame with a detector.
6. Cut the frame with the grinder in the head and in both jambs, working slowly without forcing the disc.
7. Break out the mortar around the profile with a chisel and hammer, a little at a time.
8. Lever out each piece with a pry bar, resting it on a timber block, never on the edge of the wall.
9. Cut the remaining lugs flush with the wall and remove any sharp edges.
10. Clean the opening, take the steel for recycling and the rubble to a recycling centre.

• Breaking out without cutting first. Trying to knock the whole frame out with a hammer leads to large chunks breaking off and cracks in the wall.
• Tools that are too heavy. A big demolition hammer in a thin or brittle wall does more harm than good.
• Levering against the edge of the opening. A pry bar without a block snaps off the corner of the wall and makes the opening wider than needed.
• Forgetting the cables. A cut cable at the light switch is a common and unpleasant setback.
• Underestimating sparks and dust. A scorched floor or a flat covered in dust is easy to avoid with proper preparation.
• Skipping protective gear. Flying metal, sparks and concrete dust put your eyes, lungs and hearing at risk.

Before the new door goes in, inspect and measure the opening. A door lining needs a straight, solid opening with the dimensions given by the manufacturer.

• No pieces of steel, lugs or protruding mortar are left in the opening
• The edges of the opening are solid, with no loose concrete
• Larger breakouts have been repaired, or it is agreed who will repair them
• The width and height of the opening match the requirements of the new frame
• The sides are plumb and the head is level
• Cables and pipes nearby are undamaged and the light switch works
• The floor and surrounding surfaces are undamaged
• The waste has been removed and the area is clean