A semi pedestal sink or basin is one with a part pedestal instead of a full pedestal. On a standard pedestal sink, the pedestal acts as a stand for the sink. Semi pedestal sinks are wall-mounted, rather than floor-mounted, and designed to save space. They are typically no more complicated to install than a full pedestal sink.
Place a piece of paper or card on the floor. Position the sink and semi pedestal on the paper, as they would be mounted to the wall, with the waste trap fitted. Draw around them carefully, indicating tap inlet positions, waste trap and pipe positions and bolt and screw holes. This is easier than holding the semi pedestal sink up to the wall while someone else draws around it. Now transfer the markings to the wall in the required mounting position. Do this with pencil, so you can erase any visible lines later.
Semi pedestal sinks are supplied with fixing kits. These may include plastic wall plugs, basin bolts, nuts, other bolts, washers, hanging brackets, screws, screw sleeves and screw caps. Imperial Bathrooms warns against using alternative fixings, because some fixing kits are not designed for load bearing. Though other items in a fixing kit are standard, basin bolts are unusual. They are headless and often have two different threads at either end. Both features give additional functionality, making them ideal for situations where the bolt sits in the wall but also within the sanitary ware in a restricted space.
Drill the required mounting holes to the sizes given in the installation guide. Ensure these do not damage the tap inlet pipes or waste outlet pipe. Make modifications as required to offset this. For example, you might have to raise the intended position of the sink, or move the tap inlet pipes. Attach the basin bolts to the wall -- within plastic wall plugs where specified -- so they are protruding by the required amount. Where a fixing bracket is also supplied, use a spirit level to ensure it is horizontal.
Work with a friend when fixing the sink to the wall. Ask the friend to hold the sink close to the wall. Connect the waste trap to the outlet pipe. Connect the tap inlet pipes to the tap. Normally, semi pedestal sinks have a mono mixer tap, although some have two taps. Have your friend sit the sink on the protruding basin bolts. Some semi pedestal sinks also have an optional basin support bracket. Slip your hand under the sink to locate the end of the first bolt. Fit a plastic washer and/or metal washer and nut on the end and tighten it. Do the same for the other basin bolt. Fit the semi pedestal over the waste trap. Screw it to the wall and fit cover caps over the screw heads.