Do I Need a Pad Foundation or Just a Masonry Pier? (MP1 Explained)

If your structural drawings reference “MP1” or show a masonry pier support without a separate concrete pad, this is intentional — and there is a good reason for it.

What Is MP1?

MP1 is a notation used on PorthouseDean drawings to indicate a masonry pier support. It means the column or post load is carried down through a brickwork or blockwork pier rather than into a discrete concrete pad at the base.

This is appropriate where the beam load at that column position is modest enough that the existing strip foundation beneath the wall can carry the extra point load — provided the pier is sized correctly and the foundation depth and width are adequate.

When a Pad Is Not Needed

A concrete pad is designed to spread a concentrated point load over a large enough area of ground that the soil bearing capacity is not exceeded. But if the existing strip footing beneath the pier is already wide enough and deep enough to carry the additional load, introducing a separate pad is unnecessary — it adds cost and excavation without benefit.

The structural drawings confirm whether the strip footing is adequate for the column load. If it is, the masonry pier sits directly on the existing strip foundation with no additional concrete work needed beneath it.

The Party Wall Advantage

There is also a practical advantage to using a masonry pier rather than a concrete pad in certain layouts. Where the column is close to a party wall, a concrete pad would need to extend outward from the column foot to spread the load — and that extension might cross the boundary line into the neighbouring property or require the neighbour’s party wall consent.

A masonry pier, which transfers load down through the wall rather than through a discrete pad, can avoid this complication entirely. The structural load travels down the existing building structure rather than into a new independent foundation.

When a Pad Is Still Needed

If the ground beneath the column is too soft for the masonry pier to carry the load adequately, or the existing strip footing is too shallow or narrow, a concrete pad becomes necessary. This is assessed on a column-by-column basis in the structural calculations.

If you need a pad but the standard size does not work in your layout, a narrow eccentric pad (wider in one direction than the other) can sometimes be designed as a change request.

Questions?

If you are unsure whether your MP1 positions need pads, contact PorthouseDean with your drawings and we will advise.