Mercantile buildings - These shall include any building or part of a building which is used as shops, stores , market , for display and sale of merchandise either wholesale or retail.

Mumti - A structure with a covering roof over a staircase and its landing built to enclose only the stairs for the purpose of providing protection from weather and not used for human habitation.

Mezzanine floor - An intermediate floor between two floor levels aqbove ground floor and at least one side of it should form an integral part of space floor /below.

Manhole - These are the masonry chambers provided at suitable location and on the line of the sewer for the purposes of inspection and cleaning the sewers.

Mansard Truss - This truss is now rarely constructed. This truss has two pitches , the lower varying from 60 degrees to 70 degrees and the upper from 30 degrees to 40 degrees. This truss is more or less a combination of king post and queen post trusses.

Mortar - It is usually a mixture of cement and sand or lime and sand , or a mixture of three. It not only acts as a cementing material but also imparts strength to the work by holding the individual bricks together to act as a homogeneous mass.

Measurement of Cement - Cement should always be measured by weight and not by volume.

Measurement of Fine Aggregates - Fine aggregates i.e. sand is normally measured by volume in case of ordinary works whereas in case of all important projects , it is measured by weight.

Measurement of Coarse Aggregates - Coarse aggregate may be measured either by volume (litres) or by weight. In case of wet aggregate , allowance for surface water should be made while determining the quantity of water to be used in the mix.

Measurement of Water - Water may be measured by weight or by volume.

Mitre - It may be defined as a cut formed at the required corner by cutting the corner of the sheet for a length of 15cm or the length of the end lap whichever is more along the vertical edge and for a width equal to the width of one corrugation along the horizontal edge of the sheet.

Mullion - It is the central member usually used in the revolving doors , which is attached with ball-bearing at the bottom and bush bearing at the top so as to enable the door to revolve smoothly without producing jerks.

Mud Plastering - This type of plastering is commonly seen in kuccha construction in villages and in other structures of temporary character. This is the cheapest form of plastering.