My technician who has sent me the draft drawing has specified trench foundations down to 2.5m along the side closest to the trees & 1.7m for the other 3 sides. 4.3.1 Compliance. Rain, rain go away. It consists of a Gen 1 grade concrete laid to a width of 650m wide and usually to a depth of 350mm, with reinforced steel to either top or bottom of the foundation or in some cases both. Strip foundations Usually wider, strip foundations use less concrete than trench fill because the base layer of concrete is thinner. they will be deeper than those of an adjoining construction. STRIP FOUNDATIONS. 1. For constructing steel grillage foundation, a trench is excavated to the calculated width and about 0.90 m - 1.50 m deep. Pad foundation refers to the foundation which is intended for sustaining concentrated loads from a single point load such as structural columns. trench fill foundations are deeper than 2.5m. A rough approximation from Spons shows Trenchblock at 305mm as 47 per square metre. It's close to the boundary between us & the neighbours who very kindly have 2 eucalyptus trees planted right up to his side of the boudary. The sum includes excavation costs, the amount of concrete required and the number of blocks needed. Strips are cheap and easy to construct.

A strip foundation is very similar to a trench fill foundation except there is a wide-based concrete or block strip in the trench instead of solid concrete. The soil must be of good capacity and linear walls are built along the strip. Strip foundations (or strip footings) are a type of shallow foundation that are used to provide a continuous, level (or sometimes stepped) strip of support to a linear structure such as a wall or closely-spaced rows of columns built centrally above. Its an alternative if you cant use a traditional strip or trench fill foundations but it's important to note that raft foundations arent suitable in all cases and usually need designing by a structural engineer. The average cost to install new foundations are: Strip foundations 95 115 per linear metre (LM) Trench fill foundations 130 160 per linear metre (LM) This is based on a width of 0.6m and includes excavation (using an excavator), cart away, and concrete costs. This is followed by the installation of upper distribution bars. A trench fill foundation is very similar to a strip fill one except that the trench is constructed with already mixed concrete built to nearly ground level. The width of strip foundation is three times the width of the wall. Strip Footings Vs Piles. Trench fill foundations are thinner in size than strip foundations but thicker in concrete. 4.3.8 Sloping ground and stepped foundations. A strip foundation is quite simply a strip of concrete placed in a trench. According to Sustainability in Foundations, a review by the BRE Trust, the trench fill foundations for a typical semi-detached house comprise some 18m3 of concrete, or the equivalent of around 3,000kg of embodied carbon dioxide (CO2). Foundations potentially use significant resources. The strip foundation is the foundation element that behaves, simultaneously, like a spread footing and a beam. Trenchfill will take a couple of hours to complete - trench blocks are roughly an hour per square metre so 4-5 days depending on complexity. Traditional Strip Foundations. However, the major design features of a strip foundation are dependent on the fact that the load transmission takes place at an angle of 45 degrees from the wall base to the soil. ab7167 Forumite. 4.3.6 Services and drainage. The sites good sandy ground also made strip foundations a practical solution. The strip foundation (inverted T-beam) behaves in a way similar to that of spread footings tied together by a connecting beam. In addition, excavated waste may need to be taken away. The overlap should be not less than: 2 x S, or; T (maximum 500mm), or; 300mm, whichever is the largest. A trench 90cm to 150 cm deep is excavated and levelled. Now fill concrete into the formwork. Trench Fill Foundations Used where ground conditions are not ideal, such as the soil being too loose or water logged. This would mean just over 6m3 of concrete which I could get pumped. A strip of reinforced concrete supports the walls. Also specified on the plans that foundation depth is subject to local site conditions and building control officer approval. This type of foundation consists of a trench that is dug with solid concrete poured inside. Costs for the original strip footing plan were 290 ready-mix, 350 in trench blocks and at least 350 (2 blokes at 175 a day) labour to lay the trench blocks plus about 60 quid sand and cement. The cost of a strip foundation is lower than that of a trench fill because it doesnt require as much concrete. If there are, or were, trees nearby, depths of up to 3m may be necessary. Once the concrete sets, the formwork can be removed. The absolute minimum thickness of this strip is 150mm. A strip footing or strip foundation is that in which a continuous strip of concrete is placed below the load-bearing walls. Best used in chalk soils and clay, it is often preferred by self-builders. See Appendix 1. Trench fill is quicker and more cost effective than traditional strip. The thickness should not be less than 500 mm and should finish 150 mm below ground level. Trench should be dug to a depth where subsoil provides sufficient load bearing capacity, usually it is 1m deep. See Appendix 2. Original house has strip foundation. Strip, trench fill or pad foundations must be cast at a minimum depth of 750mm in low plasticity clays, 900mm depth in medium, and British Standard 8004 recommends a minimum depth of 1m for foundations in the highest risk areas. The same linear metre with trenchfill is about 56 based on 80/cube for concrete. Please note that all of the loading figures given here may not apply to your project and should be checked by an architect on Blockwork is built up to ground level. 4.3.7 Safe transmission of loads. 4. This type of foundation minimises the excavation required, as bricklayers are not required to access the trench to lay We are planning on digging foundations 1m deep with a strip foundation at the bottom of the trench. Depth of the trench can range, although it should be at least 40 inches deep 24 inches wide. Typically, concrete is poured to within 150 mm of the surface ground level. For example, in clay of low to medium shrinkage potential, or in perimeter zone of the tree root system. 4.3.3 Ground conditions. reinforced trench fill could be employed. Piling is increasingly becoming the preferred alternative to the traditional deep and dangerous strip footings. Trench Fill Foundations. The lower level of the stepped foundation is overlapped by the upper level by thickness or height. The thickness of strip foundation is minimum 150mm. Foundations should be designed by an engineer in accordance with Technical Requirement R5 where: buildings exceed three storeys in height. Strip Foundation. Bottom of the trench is rammed and leveled. Trench Fill Foundation. 8 March 2011 at 10:02PM. House Plan 5269. For instance, closely-spaced columns render the use of pad foundation inappropriate and strip foundation may be a better alternative. New home foundation cost calculator 3. These foundations are reinforced with steel to help reduce the loading per m square.

Load is transmitted at 45 degrees angle from the base of the wall. This chapter gives guidance on meeting the Technical Requirements for strip and trench fill foundations. Like trench fills, they reduce brick laying below ground and dont require specialised equipment. Wide Strip Foundations Used where ground conditions are not ideal, such as the soil being soft Are used to distribute the load over a larger area. Minimum depth of 450mm shall be used for foundation if the area prone to frost so as to protect the foundation. This type of foundation consists of a trench that is dug with solid concrete poured inside. Blockwork is built up to ground level. A trench fill foundation is very similar to a strip fill one except that the trench is constructed with already mixed concrete built to nearly ground level. 2. 3. Piles are generally more expensive than a strip foundation, I can say no more than that without knowing the depths quantity etc. Strip foundations are a fairly rudimentary type of shallow foundation that are used to provide a continuous, level (or sometimes stepped) strip of support to a linear structure such as a wall or closely-spaced rows of columns built centrally above them.

2,080 Square Foot, 3 Bedroom, 2.1 Bedroom Home. In general, the depth of a traditional strip foundation is greater than or equal to the walls overall width, and the foundations width is generally three times that of the supporting wall. Good ground conditions are important in strip foundations, because the sides of the trench play a big part in supporting the load. Foundation bottoms should be horizontal and steps, as near as possible, vertical. If you have ever wondered how tower buildings stand up, then part of the answer could be piled foundations. Strip foundations can be either traditional strip or trench fill and both can be stepped. Trench fill foundations work out slightly cheaper than traditional strip foundations, and are much faster to build. NB The strip footings and trench fill costs both include all work to oversite and slab, so the costs are directly comparable on a like for like basis with the stage a raft foundation takes you to. A shallow foundation, such as the strip foundation, needs durable and stable soil to support it. 4.3.4 Hazardous ground. 0. Strip foundations are used where soil has good bearing capacity. As the name suggests, the formation is in a strip of linear structure that ultimately serves to spread the weight across the total area of the soil. In a normal state, the soil stress on a strip foundation is distributed symmetrically and is greater near the load-bearing columns. Tim Doherty explains how these work by Tim Doherty. They also work perfectly for areas where water tables keep basements from being feasible. If standard strip or trench fill foundations arent suitable for your site, deep piled ones may be needed instead. A strip foundation is the simplest form of house foundation. Pile foundations. It says: d) Foundations stepped on elevation should overlap by twice the height of the step, by the thickness of the foundation, or 300mm whichever is the greater. Guidance is given on how this should be done in Approved Document A 2E2 (d-e). In comparison to strip foundation, trench fill foundation is thinner in size but thicker in concrete. Ground level at time of casting foundations Trench fill foundations are a type of shallow foundation that avoids bricklaying below ground by instead almost completely filling the trench excavation with concrete.