Indy Total Construction

Because the tile you want to replace will be hooked over the batten, you need some means of lifting the adjacent tiles sufficiently to be able to lift the broken one from the batten. The best method is with wooden wedges which you can cut from lengths of 2 x lin batten, about 6in long. You will need two of these and more if the tiles are of the interlocking type.

Push the wedges beneath the tiles of the course above the broken one so there is a big enough gap for the nibs (lugs along the top edge edge of the tile) to clear the batten. Lift the tile up and remove it. If you can not get hold of it because the end has broken off, slide the blade of a bricklayer’s trowel underneath the remaining portion and use this to lift it clear.

If it is nailed in place, try wiggling it from side to side, which may pull the nails free. If not, you will have to cut through the nails with a slate ripper, a pair of pincers or a hacksaw blade.

If the tile is of the interlocking type, you will have to wedge up one of its neighbors to free it.

Fit the replacement tile by lifting it into place with the trowel blade, hooking the nibs over the batten — without nailing; the tiles above will hold it fast.

Remove the wedges carefully to lower the surrounding tiles, making sure any interlocking ridges are properly engaged and that all tiles are sitting flat.

To remove a broken slate you will need a tool called a slate ripper. This has a thin, barbed blade for cutting through the two fixing nails, which are hidden by the slates above. Slide the ripper up under the broken slate, feeling for the nails. Hook the blade over one and tug downwards sharply to slice through it. Repeat for the second nail and slide the slate out.

If you have to cut the slate to size, scribe the size on its face and set it over the edge of a wooden batten; cut along the line with the heel of a trowel.

The new slate cannot be nailed in place because of the slates above. Instead, it is retained by a lead strip measuring 9 x lin. Nail this to the batten (visible below the two exposed slates) with a galvanized nail.

Carefully lift the slates above and slide the new one into place so that the beveled edge along the bottom is uppermost. Bend up the end of the lead strip to retain it then make a second bend for extra strength.

Slates at the gable end of a roof will need a horizontal clip to stop them from sliding off the edge.

Finishing an Imperial ceiling with a coat of plaster is carried out in a similar manner to finishing off a drywall partition. However, when working above your head (which often presents difficulties of its own) it is best to apply small amounts of plaster at a time to avoid tiring your arms.

Deal with the joints first, spreading a thin layer of plaster down the center of each one and pressing lengths of 2in wide nylon mesh or paper tape into the wet plaster with your trowel. Lightly trowel over the tape then apply another thin layer of plaster on top.

Divide into handy bays; fill in each bay with a thin layer of plaster, but not over the joints. Hold the trowel blade at 30° to the surface of the ceiling; the back edge about 1/Gin clear of the board to provide an even layer. Reduce the blade angle as the plaster spreads and pinch the back edge in as you complete the stroke to stop the plaster falling off. Work away from you to avoid flicking plaster into your face.

When you have filled in all the bays, go over the entire ceiling with another thin layer of plaster. Rule it off with a long metal straightedge to remove the high patches and show up the low spots, which should be filled with a thin coat of plaster.

How you treat the angle between the ceiling and walls depends on whether you are replastering the walls at the same time or not. If not, simply run the corner of the trowel blade along the angle from the ceiling and wall sides to cut out the angle neatly. If you are replastering the wall as well, lay on the floating coat then tape the joint between the wall and ceiling before applying the finish coats. Finish the corner as normal.

Finally, polish the hardened plaster with a clean, wetted trowel blade.

If you intend papering or painting directly over the drywall, the joints must first be made to “disappear”. For this you will need drywall joint compound, paper jointing tape and joint finish (see below).

First spread a layer of compound down the seam and, with a taping knife, press the tape into it. Apply another layer of compound over the top, feathering the edges by going over them with a damp sponge.

When the compound has dried, apply a finishing layer, feathering its edges in the same way. Treat the nail head depressions with compound and finish in the same manner.

At the angles between wall and ceiling, fill large gaps with compound; then apply compound to both wall and ceiling and press a creased length of tape into it. Apply two more layers of compound to wall and ceiling, feathering the edges of each one.

There are two types of ceiling construction, depending on their age. Early ceilings were made by nailing thin strips of wood (laths) to the joists so that there were narrow gaps between them. Plaster, often reinforced with animal hair, was then spread over the laths and forced through the gaps in between. The ridges so formed are called “nibs” and these hold the ceiling together.

The more modern method of constructing a ceiling is to nail sheets of gypsum board to the joists and cover them with a thin skim coat of plaster.

Cracks are the most common form of damage found in a ceiling and if they are only fine they can be filled with a filler compound. However, if they are wide and cover a large area of the ceiling the structure will be dangerously weak and should be replaced.

If a plasterboard ceiling sags it is probably because the fixing nails have loosened. Refix the affected area by renailing with 2in drywall nails spaced 6in apart.

If plaster has fallen away from the laths but they appear to be in good condition, replaster them after cutting back the original plaster to make a regular shape and reach sound plaster. Undercut the edges of the plaster and make sure there is no old plaster left between the laths. Then treat the area with an adhesive.

When plastering always work across the laths, spreading on a thin coat of bonding plaster first and keying it with a scratch comb made by knocking a row of nails into the edge of a short batten. Apply another coat of bonding plaster and key this with a devilling float, pressing it down to allow for two thin finishing coats. Polish these when hard with a wetted steel trowel.

If the walls running across the ends of the beam are load bearing, it may be possible to cut directly into them to form bearings. In thi situationa longer than normal padstone should be used to spread the load sideways, or it may be necessary to add some extra strengthening by toothing in a shallow pier.

You must make the complete opening while the load above is still supported by the temporary props. It is essential to have all the necessary tools, equipment and materials to hand so that you can proceed quickly with the job.

At floor level, either trim the masonry off flush with a solid floor, or just below a wooden one. In the latter case, take care not to break through any water proofing membrane.

If there is a difference of level between the floors of the two rooms, either build a wooden step or cast a concrete one in situ.

With the masonry removed, you can make the bearings. Lifting the beam into place will be heavy work so it is as well to do a little preparation beforehand. To avoid the need for lifting the beam from floor level to the ceiling in one go, support it on trestles or pairs of stepladders, setting it so that you can get hold of it easily.

Set the coarse adjustment of the jack posts that will support the beam so that they can be set in place quickly and the fine adjustment made without fuss.

Lift the beam into place on the capstones and check that it is square across the room by taking measurements from nearby fixed points. Set the jack posts in place and tighten them until the beam comes up tight against the joists or masonry above. Check that the beam is completely level and make any fine adjustments with the posts.

At this stage you can remove the posts holding the joists, but leave any needles in place.

Trowel a layer of mortar between the top of the capstone and the underside of the beam and then tap pieces of slate into place to wedge the beam tightly upwards. You may need to insert two or even three pieces. Do the same at the other bearing, making sure it forms as tight a wedge as possible.

Finish off by pointing more mortar round the ends of the beam and capstone. If it is set on bearings cut into the end walls, fill the cavities around the ends of the beam with whole bricks or offcuts and more mortar, pointing it neatly.

With the bearings finished, check along the top of the beam to make sure it is fully supporting the joists or masonry above. If there are any gaps they must be wedged out too. In the case of masonry, use mortar and more slate wedges. If it is a wood floor, drive slates between the beam and any joists that are not otherwise supported.

Allow the mortar to harden for at least two days before removing the jack posts from below the beam together with any needles and their posts. Fill the needle holes with brick offcuts and mortar, then make good the ceiling, adjacent walls and floor.

If you have used a steel beam, clad this in a material that will protect it from fire: do not leave it exposed. The usual method is to clad the beam with gypsum board on a wooden framework nailed to wedges hammered into the sides of the beam.

The corners of the gypsum board should be taped or fitted with metal corner beads and finish it.

Concrete beams can be directly plastered over, their surfaces being rough enough to provide a key for the floating and finish coats.

When the beam has been plastered, finish the piers as well, using battens or special beads to form the corners. (Beading is probably best since the piers project into the room slightly and are, therefore, more likely to be knocked.)

Finally, cut the baseboards to fit around the base of each pier.

If the wall is of the non-load-bearing variety, the job will be much simpler since there is no need to fit a beam.

With a masonry wall, simply hack off the plaster and remove it brick by brick or block by block from the ceiling down. Cut out any metal ties holding the partition to the end walls, or cut through any bricks or blocks that have been toothed into them. At floor level, trim the masonry off flush — it may just sit on top of the floor anyway.

Replace the ceiling, if necessary, by cutting back to the nearby joists and nailing on a fresh strip of gypsum board. Finish it off with a skim coat of plaster and repair any damage to the walls.

If the wall is a wood-framed stud partition, simply lever off the cladding and prise apart or unscrew the frame. Fill any holes in the adjoining walls and redecorate.

To plaster a newly built wall you will not have to do any preparation work to it at all before you fix wooden grounds or metal lath in place.

Then the masonry should be dampened by splashing on clean water with a paintbrush. This will help slow down the rate at which the wall absorbs moisture from the plaster, preventing it from drying out too quickly and possibly cracking.

It is a good idea to practice scooping plaster from the hawk and applying it to the wall before you attempt the job for real. Set the loaded trowel against the wall so that the bottom corner of the blade rests on the ground or bead and the blade is at an angle of about 30° to the wall surface. Move the blade upwards to spread a vertical strip of plaster next to the thickness guide, keeping the blade resting on the guide and gradually reducing its angle as the plaster spreads.

Apply more strips of plaster in the same way, working upwards from the bottom and across the bay adding a good thickness of plaster to the wall.

When the bay is finished, use the long wooden rule to strike it off level with the thickness guides. Place it across the guides and draw it upwards, moving it from side to side in a sawing motion as you go. This will level off the high spots and accentuate the dips. Add more plaster and repeat the process until level.

Before it sets, key the surface for the finishing coat by passing a wooden float, with nails knocked through its face, over the plaster to leave score lines.

When the floating coat has hardened (it should take about two hours), you can apply the finishing coat. This is done in exactly the same way as plastering wallboard, applying two thin coats of Finish plaster to produce a polished, flat and hard surface.

Directions:

1. Scooping plaster from the hawk; put the trowel into the plaster and scoop forwards and upwards.

2. Practising applying paster to the wall; work upwards from waist-height, starting with the trowel at 30 degrees to the wall.

3. As you apply the plaster, tilt the trowel more parallel to the wall surface; keep the hawk close to the wall to catch droppings.

4. Applying the plaster in vertical strips; at the end of each stroke, press the lower edge of the trowel to firm the plaster onto the wall.

5. Ruling off the completed bay; use a straight-edge with a sawing motion to lower any high spots and to show up areas with too little plaster.

6. Scoring the surface to provide a key for the finishing coat; the nails should protrude in through the float.

7. Filling the gap left after taking off the ground batten; level off with the trowel, flush with the hardened plaster on each side.

8. Applying the finishing coat; work from bottom to top and cover the floating coat with a thin layer; apply a second coat. 9 Polishing the finishing coat; wet the surface sufficiently to remove ridges and marks and polish firmly with a perfectly clean, flat trowel.

The main problem when plastering corners, whether external or internal, is getting a good, sharp angle. You will face a similar problem at the junction between the wall and ceiling. However, the techniques for dealing with both types of corner are not difficult to master.

There are two forms of guide you can use for forming an external corner: a timber batten or purpose-made metal beading.

The wooden batten is used as a thickness guide for the floating coat then the finishing coat on each wall. Nail it on to one wall so that it projects by the right amount beyond the other and use as a ground for that wall. Then, when the plaster has set, move it round the corner and repeat the process. Any sharp ridges on the apex of the corner should be sliced off with the trowel blade and then the corner rounded off with a block plane or rasp. With wallboard you must tape the angle first.

Two depths of metal beading are available to deal with masonry or gypsum board-clad walls and they can be fixed in place with plaster or galvanized nails. On wallboard, nails must be used. The beading acts as a ground for the floating coat on masonry walls. Before this hardens, cut back the level to allow for the finish coat. Trowel off flush with beading, leaving the nose exposed to provide a knock-resistant corner.

For dealing with internal corners, you need a long wood rule. Use this to rule the floating coat outwards from the corner.

After keying the floating coat, cut out the angle by running the corner of the trowel blade up and down it, holding the blade flat against each wall in turn. This will produce a sharp angle. The finish coat should be treated in the same manner. The final job is to hold the short side of the blade against one wall so the long side is just touching the fresh plaster. Hold the blade at 30′-40° and gently run it down the corner.

For finishing corners where both walls have been plastered, use a special V=shaped angle trowel. This produces a constant right angle in the fresh plaster. Load a small amount of plaster onto the angled blade of the trowel and run it lightly down the angle.

Directions:

1. Reinforcing the external corner of a masonry wall with angle-bead; set it into blobs of plaster, 12in apart.

2. Plastering one wall; work away from the corner, using the nose of the bead as a thickness guide.

3. Plastering the adjoining wall in the same way: leave the nose just visible. Score the surface of both walls.

4. Applying the finishing coat, this time covering the nose: round off the corner by running a wet finger along the bead.

5. Securing angle-bead to the internal corner with galvanized nails; nail through the drywall into the stud.

6. Applying a coat of finishing plaster, working away from the corner; the nose should be left visible in this case.

You need only apply two very thin finishing coats directly over the drywall.

The plaster needed for the job is sold ready mixed or in a powder form requiring only the addition of water. It is mixed in the same way as other plasters and has a creamy texture.

Because you are only applying a finishing coat to the drywall board there is no need for thickness guides, except at any external corners.

It is a good idea to practice scooping the plaster from the hawk on to the trowel first, using a spare piece of drywall to try your hand at spreading the plaster and making it stick to the board_ The technique is to hold the hawk in your left hand (or right if you are left handed) so the top is level and set the trowel blade on edge, so it is at right angles to the top of the hawk. Use the trowel to push some plaster towards the edge of the hawk, scooping it off at the same time as tilting the hawk towards you. The whole is done in one smooth movement.

The first job is to seal the joints between the individual panels of gypsum board, reinforcing them with perforated paper tape or nylon tape to prevent the plaster cracking. The standard paper tape is available in 2in wide rolls of 50-500 feet.

Cut strips of tape to run the length of each joint, including any horizontal ones, before you begin plastering. They must be exactly the right length and should not overlap or be folded, otherwise the plaster will not grip the wall properly.

To seal the joint, spread a thin layer of plaster, about 4in wide, along it from bottom to-top. Hold the trowel so that the blade is at an angle of about 30° to the wall, reducing it as you move up the joint and the plaster on the trowel thins.

While the plaster is still wet, press the tape into it. The easiest way to do this is by draping one end over the blade of the trowel and pressing this into the plaster at the ceiling. Then gently slide the trowel down the plaster, positioning the tape with your other hand. Once the tape is in place, run the trowel carefully up the plaster to make sure it is bedded properly. Treat all the other joints between the panels in the same way.

When the taped joints have dried — which should take about 11/2 hours — fill in the areas between them with more plaster. Work upwards from the floor, spreading the plaster in thin vertical strips and being careful not to build up ridges at the joint positions. Stop just short of the ceiling and work downwards from there to get a clean, sharp angle.

Unless you are working on a very small area, by the time you have finished putting on the first coat, the area you started on will be ready for the second coat. This should be about 1/sin thick and applied with long, sweeping strokes to eliminate ridges. Start at the bottom corner of the wall and work upwards and along to make one continuous coating.

Allow the plaster to set slightly and then go back over it with a clean trowel to smooth off the surface. Finally, when it has hardened fully, “polish” the surface by splashing clean water on to it with a paintbrush (about 4in wide) then sweep the trowel back and forth lightly. This will give a smooth, matt finish ready for decoration.

One problem the beginner faces when tackling a plastering job is that of producing a floating coat that is uniform in thickness and level over the entire wall. The answer is to divide the wall into sections and use the dividers as depth guides.

Space the dividers as close together or as far apart as you like, but a suitable distance is about 3ft.

There are various methods for dividing the wall into bays, and a traditional way is to trowel narrow strips of plaster from floor to ceiling. Known as “screeds”, these strips of plaster are allowed to harden, then more plaster is spread on the wall between them and brought up to their level, using a long straightedge placed across the screeds to check.

The problem with the screening method is being able to get the plaster strips to the right thickness in the first place. Small blocks of wood, known as “dots”, can be fixed to the wall at the top and bottom of the screed position and used as thickness guides by setting a straightedge between them.

An easier way is to use wooden “grounds”. These are lengths of planed, %in thick by about 2in wide softwood, which are fixed to the wall with masonry nails. Since you plaster only one bay at a time, you need only two grounds per wall and, therefore, you can move them along as you work.

After setting out the first bay, you can apply a floating coat between the two wooden grounds, striking it off level with a long wooden straightedge called a “rule”. Then, having let the plaster harden off for a while, you should carefully pull one ground from the wall and nail it back on further along the wall to make a second bay.

Continue applying the floating coat in this way until you have completed the job.

When fitting wooden grounds it is essential that they are set vertically, otherwise the plaster surface will be out of true. Use a long mason’s level to check that they are upright and, if necessary, slip small wooden shims as packing pieces behind the grounds to bring them into line.

An alternative to using wood grounds is the metal screed bead which you can buy from your builder’s supply house. It does the same job as the ground but is designed to be left in place on the wall; it disappears under the finishing coat of plaster.

The center of the bead is formed into a raised, inverted U-shape, the depth of which is equal to the depth of the floating coat, and on each side there is expanded metal mesh. You can cut it by snipping through the mesh with metal snips then sawing through the bead with a hacksaw.

Beading is fixed to the wall with “dabs” — blobs of plaster troweled on to the wall. Push the beading into the dabs then check with a level.

Allow the plaster to harden off and then use the beads as thickness guides for the floating coat.

Before laying the blocks it is as well to carry out a dummy run on the first two courses, so you will know how best to arrange them to keep the number of cut blocks to a minimum. Set them out along the layer of mortar in line with the scribed mark, spacing them a finger-thickness apart.

If the partition is to have a door in it, now is the time to position the frame. Nail battens across the corners of the frame and across the bottom to hold it square and prop it up with a batten nailed to the top.

Now begin laying the blocks properly. It is best to build up about four courses of blocks at each end of the partition first and then stretch a stringline between them as a guide for the blocks in the middle.

Trowel a layer of mortar onto the original thin layer and “butter” the end of the first block with more mortar. Set the block in place against the scribed line and against the wall to form a neat mortar joint. Tap the block level and upright with the handle of the trowel. Repeat the procedure for the next block in the course and lay two or three more before working back towards the wall with the second, third and fourth courses. Collect the mortar that is squeezed out from between the blocks for reuse.

Make sure the blocks butt up to the guide batten and check them every now and again with a mason’s level to ensure that you are keeping the courses upright and level. Tie each alternate course to the wall with galvanized metal wall ties. Similarly secure the door frame to the blockwork; build up the center of the partition.

If you need to cut any blocks, do this with a bricklayer’s chisel and hammer. Measure up the block and scribe a cutting line on all four sides with the end of the chisel. Then tap gently along this line with the chisel. Finally, lay the block face up, set the chisel in the center of the cutting line and strike it a sharp blow which will separate the two halves of the block.

Directions:

1. Dry-laying to check for fit; allow a finger-thickness between blocks for mortar. Vertical battens give support until the mortar hardens.

2. Spreading the mortar bed on the floor; scribe the line of one face of the wall in the mortar with the point of the trowel.

3. “Buttering” one end with mortar before laying the block; place this end against the previous block.

4. Laying the block on the mortar bed, flush with the scribed line.

5. Tamping the block level with the adjacent block using the trowel handle; check each block as it is laid with a spirit-level.

6. Securing a metal frame-clamp to the side wall; tie alternate courses in this way.

7. Checking the face of the blockwork for alignment; use a long spirit-level or straight-edge and check in a number of directions.

8. Nail temporary “strainer” battens across a door-frame to keep it square and support it in an upright position with a plank nailed to the top.

9. A door-height opening needs a lintel above it to support the blockwork; a course of bricks on top will align with the blockwork.

Although a wood-framed partition is easy to build, it does not provide the most effective sound insulation and it will need extra strengthening if it is to carry shelves or cabinets. In situations such as this, a partition built from lightweight concrete blocks is much more suitable. However, you cannot build such a partition on an upper floor, since even a reinforced concrete floor is unlikely to be strong enough to carry the load of a concrete block partition. A concrete first floor makes an ideal foundation and even a suspended wood first floor will do if a full-width wood sole plate is put down first, but check with your local Code.

Before starting work, the floor, walls and ceiling should be stripped of all coverings and any coving and base cut away with a chisel to clear the blocks. The easiest way to mark the position of the partition is

with a chalked plumbline, snapping it against the floor to leave two parallel chalk lines the width of the blocks. Continue these lines up the walls and across the ceiling making sure they are vertical.

For strength, it is best to tie the partition to adjacent walls by cutting recesses in them to accept the end blocks of alternate courses or similarly by using galvanized metal ties screwed to the walls and buried in the blockwork mortar joints. Nailing a guide batten to the wall against one of the chalk lines is also a good idea to help with the alignment.

Trowel a 6in wide layer of mortar (1 part masonry cement: 6 parts soft sand) across the floor to span the chalk lines on it, leveling it out to about 1/2 an inch thick. Then scribe a guide line through the mortar in line with the chalk marks on the end walls, using the point of your trowel and a long straight-edged plank.

There are many different types of concrete block to choose from, but the best types for building an internal partition are known as aerated blocks (A).

These are light in weight, so they are easy to handle — an important quality since they are twice the size of a normal brick. This fact also means that you can build a full-height partition relatively quickly. You can drill them, knock nails into them or, using a general-purpose saw, cut channels in them (B) to conceal electric cables and pipe work. Sound will not pass through them as easily as it would a woodframed partition, nor will heat.

Aerated blocks should be laid in the same manner as bricks in a “stretcher” bond pattern with mortar joints. Their normal size is 17 x 81/2 x 4in. For finishing, you can either plaster them directly or nail on battens and fix a gypsum board cladding to the battens.