GB2450328A - Concrete building block for one-handed laying - Google Patents

Abstract

A dense high thermal mass building block has a weight commensurate with the ability to lay the block in a one handed bricklaying manner. The block may also contain vertical holes and slots to increase the face area and grips or slots enabling the block to be hand split into portions. Creases 1 on either the outer or inner face of the block holes enable a clean break. Lips or grips 2 may be provided at the top outer edges of the central holes to assist in lifting the block. Alternatively, retractable handles may be set in the top middle of the blocks to facilitate one handed lifting. Further, a building block has projecting and indented interlocking perpends that may obviate the need for mortared perpend joints and these perpends may coincide with the vertical holes and slots so that shorter cut blocks coincide at perpends.

Description

Improvement to concrete blocks and block laying The past century has

seen the development of the concrete block in construction and in particular the lightweight aircrete block as cavity walls became widespread.

With ever increasing standards of thermal insulation required, the role of the aircrete block as the loadbearing and insulation element of the cavity wall is falling short.

Also there is growing acknowledgment that high thermal mass within the insulated envelope of a building is important in retaining both passive solar energy and in situ imput heating, and in smoothing out day/night temperatures fluctuations to provide a comfortable environment without recourse to booster heating or air conditioning Lightweight blocks, being able to be lifted by one hand, can be laid in a bricklaying manner, that is the bed and perpend joint can be prepared with the trowel hand, the block lifted into position with the free hand, with the trowel hand immediately at the ready to tamp the block level and upright. Heavy concrete blocks have to be lifted by using both hands, requiring the trowel to be laid aside. This delay in retrieving the trowel or lump hammer can cause delay and problems, in that, particularly in warm dry weather and when the blocks are dry, the rapid absorption of water from the mortar can stiffen the mortar in that delay, and make subsequent leveling and positioning more difficult and time consuming.

If the mortar is made excessively wet, to compensate for this, firstly it is more difficult to apply and secondly the blocks can slip and slide and sink annoyingly.

The improvements herein described are to design a dense high thermal mass block with as large a surface area as possible appropriate to its application, which can be laid in a bricklaying manner, ie lifted in position by one hand with a trowel, or Iwnp hammer or level at the ready with the other, enabling accurate positioning before the mortar has stiffened.

The improvements are also mindful of the impinging Health and Safety Executive regulations which regulate block laying activities. Builders merchants when blocks over a certain weight, which are deemed a two man laying operation are ordered are obliged to record delivery site to assist the HSE in carrying out spot checks on these activities.

A preferred embodiment, with a specific building system of external insulation involved is herein described and illustrated on drawing No 1.

As aforementioned there is a growing need for thermal mass #rithe structure to be contained within the insulated building envelope. There is a system called I.C.F.

(Insulated Concrete Formwork) that employs polystyrene interlocking hollow wall formers with poured concrete into hollows, but to utilise the thermal rns of the poured concrete structure the inner face of the polystyrene former has to be subsequently laboriously removed.

The building structure herein envisaged is a dense concrete block inner structure with external insulation and render finish subsequently applied.

In this construction there is a need to employ wider blocks than in normal cavity construction, not necessarily for completed structural integrity of the building when floors and roofs are tied in, but merely for the structural stability of the walls during construction, ie prevent them from blowing over.

It is envisaged that as against a normal 4" wide block a 6" wide block will suffice in most UK prevailing wind conditions.

As aforementioned the aim is to provide as large a surface areas as possible of a high mass block compatible with a one hand bricklaying operation.

Most concrete blocks presently employed are 9" high to conespond with brick courses. It is envisaged that the proposed blocks, to be liftable by one hand will be lower than that, may be 6".

Vertical holes, round, oval, diamond or hexagonal shaped or a combination of these shapes are introduced to reduce weight. Furthermore these holes provide weak points enabling the blocks to be hand split into portions. This is to be compared with existing hollow concrete blocks which have rectangular holes or slots, which are veiy difficult to hand cut with a hammer and bolster anywhere other than against the cross member junctions.

Creases 1 on either the outer or inner face or both of the block holes, may be formed in manufacture to enable a clean break possibly with the mere tap of a hammer or trowel.

Since the blocks are generally wider than a comfortable hand span, lips or grips 2 are provided at the top outer edges of the central holes, or inset into the middle of the top of the blocks to assist lifting.

Perpend mortar joints to blocks traditionally help in structural stability but are also important in airtightness and sound tightness.

Maintaining fully flush perpend joints is the most difficult and time consuming aspect of blocldaymg.

Perpend joints serve in traditional applications three purposes: weatherproofing for external blockwork as well as airtightness and sound tightness in cavity and internal walls. They have limited effect on the structural stability of the wall which is primarily provided by staggered blockbonding.

In the application aforementioned ie blockwork that will have a wet internal plaster face and external insulated and rendered face, airtightness and sound tightness of perpend joints will not be critical.

The same will apply to a number of applications particularly where wet plaster or render is to be applied.

Drawing No 1 illustrates blocks with closefitting interlocking indents/protrusions that will assist with structural cohesion whilst eliminating the need for mortared perpends.

These protrusions/indents at the ends of the blocks will be the same as, and coincide with the holes within the blocks so thaI where smaller blocks are cut at the centre of the holes, these protrusions/indents will continue to interlock/coincide.

Retractable handles may be set in the top middle of the blocks for lifting.

Claims (8)

1. Claims 1. A dense high thermal mass building block that has maximum

   face area dependent on its bed width and of a weight commensurate with the ability to lay the block in a one-handed bricklaying manner.
2. 2. A building block as in claim 1 that contains vertical holes and slots of various shapes that reduce its weight to maximise its face area dependent on its bed width and commensurate with the ability to lay the block in a one handed bricklaying manner.
3. 3. A building block as in claim 1 and 2 that contains grips slots or lips in its upper surface to facilitate one handed lifting particularly if the block is wider than a comfortable hand grip.
4. 4. A building block as in claims 1,2 & 3 that has grooves or creases coinciding with the centre of the vertical holes, slots or lips to facilitate the cutting of these blocks in those positions. * **
5. 5. A building block as in the foregoing claims that has a retractable handle in the middle of the upper surface to facilitate one handed lifting. S..

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6. 6. A building block that contains perpend projections and indents that :.::. interlock and align the block in a close fitting manner and that may obviate the need for mortared perpend joints.
7. 7. A building block as in claim 6 wherein the perpend projection and indents coiicjde with vertical holes and slots so that cut blocks coincide at perpend joints. * *. * * S * * S ** *

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