When blocking up a doorway or entryway in a brick wall, it is important to make sure that the new section is tied into the existing wall. This can be done in a variety of ways, as we will show here. If the wall is not structural (i.e. it is decorative), the method used to tie it together is not quite as important.
The other important element of blocking up doorways in brick walls is making sure that the new section is lined up with the wall on either side, particularly if it will be plastered over at a later date.
Step 1 – Choosing Materials
If at all possible, match the bricks to be used to block the doorway to the bricks used in the rest of the wall. Bricks suitable for building walls are generally of a standard size, but if the new bricks don’t match the existing bricks, you are only giving yourself more problems and more work.
Mismatched bricks may result in cracks forming in the mortar or in any plaster applied over the bricks. The same applies if filling an opening in a block wall.
The next thing to decide is how you are going to tie the walls together. If you plan to cut half bricks out of the surrounding wall and bond the new section in, you only need the bricks and your mortar. If you prefer to go for the easier option of tying the sections of wall together using nails, frame cramps or a wall connector system, you need to decide which is best.
If the surrounding wall is solid and in good condition, both nail ties and frame cramps are perfectly good. If the wall is not in such great condition, it might be better to use a call connector system (available from many DIY chains).
Step 2 – Preparing the Opening
If the doorway or opening in the wall is bare brick, you can simply clean up the inside faces by brushing them down and removing any loose mortar and dirt. If the doorway has had a door in it (which we will assume has been removed), you will need to carefully take down the architrave and door lining before you can start filling the gap.
Prise off the architrave using a pry bar and then saw through the door jamb and lining near the top of the doorway. Prise this away with a pry bar and discard it. If the doorway is an original feature of the house, the bottom of the linings might extend below the flooring. If this is the case, saw through the linings flush with the floor. Saw through the threshold (if there is one) and pry it up out of the way.
Cut back the plaster around the opening by about 150mm. Don’t worry too much if this is not neat or straight as an irregular edge can help to disguise the outline of the doorway when re-plastering. Finally, clean off the inside faces of the bricks using an old brush, and remove any loose mortar.
Step 3 – Brick Bond Method
The best way to fill the opening is to use the brick bond method. This mean removing half bricks from either side of the opening, every fourth course, all the way up the doorway. The best way to remove half bricks is by drilling out the mortar around each one and then knocking them out with a lump hammer and cold chisel. This method should give you the strongest finished result.
Start to lay your new bricks in the opening, matching the level of the existing brick courses. If the floor level in the opening is lower than the first course of bricks, nail a timber sill in place to act as the foundation for the first course. If you are very lucky, the opening will be exactly 3-4 bricks wide (plus room for the mortar) and you won’t need to cut any bricks.
When you reach the fourth course, where the half brick was removed from the wall on either side, butter a brick with mortar and slide it into the gap. On these courses, you may need to cut bricks to make them fit. Just don’t cut the brick which is inserted into the wall.
Continue to lay brick courses in this way until the whole opening has been filled.
Step 4 – Wall Tie Method
If you don’t want to start cutting out half bricks from the wall on either side of the opening, you can use nail ties, frame cramps or wall connectors to tie the wall together (as discussed above). Nail ties are simply 100mm cut clasp nails which are driven into the mortar of every fourth course of the existing wall. Use two nails each time, driving them in at an angle so that they stick out of the mortar in a V shape.
Frame cramps are L-shaped brackets that are screwed to the inside face of the doorway and project out into the opening. Make sure that when they are fixed into place, on every fourth course, the projecting part is level with a line of mortar.
A wall connector system works in a similar way. The difference being that a long metal strip is fixed to the inside face of the doorway and projecting tabs are fixed to this at various heights. As with frame cramps, you need to make sure that the projecting tabs match up with a line of mortar.
Lay bricks in courses, as shown in the previous method, and simply bed the nail ties or frame cramps into the mortar of the course they are on.
Step 5 – Finishing the Opening
Leave the mortar to dry and then brush down the new wall. Apply a coat of basecoat plaster, with a coat if finishing plaster over the top. This should hopefully match in to the plaster on the surrounding wall. Take care over this part of the job, as it is often the plaster which will show up the outline of the old doorway.
When this is dry, fit two complete lengths of skirting board along the bottom of the wall (if required). You can now paint or paper over the wall to further disguise the old opening. When blocking up a doorway in an exterior wall (a garden wall for example), you can help to disguise the new section by rubbing dirt into the mortar once it is dry, and then brushing it down with a stiff broom.
