How to decorate your Interior Walls?

(i) Load bearing:

Carrying super imposed loads from floors and roofs Made of brick, concrete, etc.

(ii) Nonload bearing:

Partition walls/panels/curtain walls/filler walls Wall boards, hard board, plaster board, insulating board. Advantages-easy to erect, not introducing moisture in to the structure, cheap.

Partition walls:

Plane brick partition 10 cm thick plastered on both side Reinforced brick partition wall. Brick nagging type Hollow (breeze) block partitions of clay, Terracota or concrete-lighter, rigid, economical, strong fire resistance, sound insulating, plastered.

Glass partition wall, metal lath and piaster partition. Galvanized Iron/Asbestos Cement Sheet partition Timber partition-Stud/Commapartation, vertical upright members are called Stud wood. Steel panel, straw board.

Trussed partitions-Quicker and cheaper to erect a wall is normally framed out with vertical 2 x 4s, called studs, which run from floor to ceiling. These are generally spaced 40 cm apart centre to centre in other words it is 40 cm from the centre of one stud to the centre of the next stud; it does not mean that it is 40 cm between studs.

This rule can vary in places-for example, in or near the corners of a room where there may not be 40 cm between the last stud and the one in the corner or near windows, doors, and other openings, where again there may not ‘be between the last wall stud and the first to frame out the opening.

Also some walls especially interior partitions that were added after the original structure may have studs spaced 60 cm apart instead of the usual 40 cm.

Remember too that doors and windows usually have additional framing in the form of doubled 2 x 4s alongside each opening, as well as double headed aero s the top of each opening. A header usually consists of two 2 x 4s nailed together after they have been placed on edge.

The sill that crosses under the window opening ,s also formed by using doubled 2 x 4s in most cases, and there may be short vertical lengths of 2 x 4, called cripple studs, nailed between the header and the top plate, as well as between the between the bottom, plate and the underside of the window sill.

Working With Gypsum Wallboard (Drywall):

Gypsum wallboard is probably one of the most widely used wall-surfacing materials, having almost entirely replaced plaster in building built over the last thirty or forty years (although it is often called Sheet rock, that is actually the brand name of one manufacturer). Gypsum board is strong and easy to work with, and much simpler than plaster to install.

It is one of the easiest ways for the building owner to finish off a newly erected partition wall (or to make a sizable patch on a plaster wall).

Gypsum-board panels are normally sold in 120 x 240 cm sheets, although larger sheets 300, 360 or 480 cm long can be specially ordered. They come in three standard thicknesses: 10, 12 and 15 mm with the 12 mm thickness being by far the most popular.

Each panel has a slight recess along its long edges, designed to make a smooth, flush joint when the joint is to be covered with the special perforated paper tape and compound sold for this purpose.

The sheets are secured with special large-headed nails. For maximum holding power there are nails that are also ringed or “threaded” and are much more effective in preventing eventual loosening or “popping.” Nails should be spaced no more than 15 cm apart along the seams, and no more than about 80 cm apart along studs at the centre of the sheet.

Plywood:

Plywood is usually available in two types- interior and exterior. The primary difference between the two is that exterior play woods are supposedly made with a more waterproof glue, and the quality of the inner plies is higher- fewer knots and other defects-thus creating a stronger panel.

Interior and exterior grades of plywood are classified according to the quality of the outside plies or layers of veneer on each side of the panel-qualities that affect appearance more than anything else. They are graded from A through D, with A the best quality and D the worst, (There is also an N quality, which is the smoothies ad finest grade of all.

It consists of all hardwood or sap wood without any knots or other defects. It is seldom stocked by local timber-yards; however, it is mostly sold through industrial channels to cabinet makers and furniture producers).

Grade A plywood has only minor blemishes that have been neatly repaired, and a smooth surface that takes paint better than any of the other grades. Grade B may have a few tight knots up to 25 mm in diameter and may also have repair plugs in places, although the overall surface is solid and fairly smooth.

Grade C allows for tight knots up to 40 mm in diameter, as well as a few splits of limited size. Grade D permits knotholes up to 65 mm across, plus other defects that may be slightly larger than those allowed in Grade C.

When you buy a full sheet of plywood you should find the grade stamped on each sheet. Two large capital letters will indicate the grade for the two sides. A sheet stamped A-A has a smooth attractive Grade A outside ply on both sides. If the appearance on one side is not as important as that on the other, then you will probably select a sheet stamped A-B or A-C. Few, if any, timber yards stock all combinations.

There is also a type of plywood known Medium Density Overlaid that has an exceptionally smooth resin-impregnated finish ideal for painting. It needs no sanding and almost eliminates the later problems of checking and splitting that often plague conventional plywood.

MDO plywood comes in exterior type only and costs more than interior types-but it is well worth the extra cost for indoor projects when you want a really smooth painted finish that won’t show cracks or checks after a few years.

Pointers on Working with Plywood:

(i) Cut plywood with a fine-tooth saw to minimize splintering and to give the cleanest possible edge. Make sure the panel is firmly supported on both sides of the cut.

(ii) If you are cutting with a hand-saw, place the panels with the face-the good side-up. A handsaw cuts on the down stroke, so any splintering will occur on the bottom side.

(iii) If you’re using a portable power saw, then cut with the face down. Power saws (circular saws as well as sabre saws) cut on the up stroke, so any splintering will occur on the top side.

(iv) When cutting panels on a table saw or radial-arm saw, however, you should to cut with the face up, because these saws cut down through the wood.

There will be occasions when it is important to avoid splintering on either face-for example, when both sides will be visible and smoothly finished. You can do this best with a portable circular or table saw equipped with a special hollow- ground blade made for cutting plywood.

The best of these give a smooth, splinter free cut that looks and feels sanded. Special fine-tooth blades for cutting plywood are also available for most sabre saws, but they cut much slower and are less likely to give you a really straight cut unless you clamp a straight edge to the plywood for a guide.

When you’re cutting with a handsaw, there are a few tricks to help minimize splintering –

(1) Make sure the saw has sharp, fine teeth

(2) Score the plywood along the cutting line on both faces with a sharp knife and a metal straightedge.

(3) Lay a strip of masking tape along the line on the back side, and saw right through it.

Splintering can also be a problem when drilling holes through plywood, so always try to drill from the good side so that any splinters will be on the back side. And when the back side is accessible, you can avid splintering entirely.

Clamp a scrap piece of timber to the back side of the plywood before you start, then drill through both pieces at once; if any splintering does occur it will be on the back of the scrap piece of wood, not on the plywood.

Another way to prevent splintering, especially when boring large-diameter holes, is to stop drilling when the tip or point of the drill bit just barely breaks through on the back side. Pull the bit out and finish drilling the hole from the other side.

Plywood Joints:

When joining plywood with nails or screws, remember that these fasteners do not hold very well when driven into the edges of the plywood. Make sure the fasteners are longer than normal, and use glue along with the nails and screws.

Better yet, try to arrange joints so that nails or screws will go into one of the faces instead, and be kept as far away from the edges as possible. When nailing drive nails in at oblique angles to each other, rather than straight in.

Joints in plywood are the strongest and neatest when formed by rabbeting or doing, rather than by merely butting one piece on top of the other. Always reinforce with glue and screws or dowels. If appearance on the inside of the joint is no problem, triangular or square blocks of wood can be glued into the inside corner.

Working With Hardboard and Particle Board:

Hardboard and particle board (sometimes referred to as flake board) are both made of real wood. Hardboard panels are made by compressing soft wood pulp into sheets under high heat and pressure after mixing it with special binders and resins.

Particle board is made by compressing wood flakes or chips with binders, again under heat and high pressure. In both cases the result is a dimensionally stable and exceptionally strong panel that has no grain, thus is less likely than plywood to crack or check on the surface.

Hardboard is also on very abrasion-resistant and is much easier than plywood to bend when curved frameworks or surfaces must have to be covered. It is most widely available in 3 mm and 6 mm. thicknesses, and usually comes in 120 cm. wide panels that are either 240 or 300 cm. long. There are also special sheets sold for floor under payment which come in either 121 x 90 cm or 121 x 120 cm. sheets.

Hardboard is made in two grades; standard and tempered. Standard is for general interior use where moisture is not a problem, while tempered is much harder and denser and has been treated with special resins that make it much more resistant to dampness and moisture. Tempered hardboard is used on outdoor projects.