₦airaland Forum

“Every person who invests in well-selected real estate in a growing section of a prosperous community adopts the surest and safest method of becoming independent, for real estate is the basis of wealth.”
-Theodore Roosevelt

“90% of all millionaires become so through owning real estate.” Andrew Carnegie

The philosophy of the rich and the poor is this: the rich invest their money and spend what is left. The poor spend their money and invest what is left.” Robert Kiyosaki

“When you invest, you are buying a day that you don’t have to work.” Aya Laraya

“Now, one thing I tell everyone is learn about real estate. Repeat after me: real estate provides the highest returns, the greatest values and the least risk.” - Armstrong Williams, entrepreneur

“The wise young man or wage earner of today invests his money in real estate.” Andrew Carnegie

“You will come to know that what appears today to be a sacrifice will prove to be the greatest investment that you will ever make.” Gordon B. Hinkley

“Every person who invests in well-selected real estate in a growing section of a prosperous community adopts the surest and safest method of becoming independent, for real estate is the basis of wealth.”
-Theodore Roosevelt

“The wise young man or wage earner of today invests his money in real estate.” Andrew Carnegie

“The wise young man or wage earner of today invests his money in real estate.” Andrew Carnegie

“You will come to know that what appears today to be a sacrifice will prove to be the greatest investment that you will ever make.” Gordon B. Hinkley

“When you invest, you are buying a day that you don’t have to work.” Aya Laraya

What Is Backfilling?
In construction, backfilling is the process of replacing or reusing the soil that is removed during building construction to strengthen and support a structure’s foundation or any other structural member.

Factors affecting Backfilling in Foundation
1.Choosing the right backfill material
2.Compacting the backfill
3.Period of backfilling

Types of Backfilling in Foundation
Based upon the type of material used for backfilling in foundation, they can be divided into,

Course Grained Soil
Coarse-grained soils include gravelly and sandy soils and range from clayey sands through the well-graded gravels of gravel-sand mixtures with little or no fines.

Fine-Graded Soils Of Low To Medium Plasticity
In organic clays of low to medium plasticity (gravelly, sandy, or silty clays and lean clays) and inorganic silts and very fine sands of low plasticity (silty or clayey fine sands and clayey silts) are included in this category.

Commercial By-Products
The use of commercial by-products, such as furnace slag or fly ash as backfill material, may be advantageous where such products are locally available and where suitable natural materials cannot be found.

Fly ash has been used as a lightweight backfill behind a 25-foot-high wall and as an additive to highly plastic clay. The suitability of these materials will depend upon the desirable characteristics of the backfill in foundation and the engineering characteristics of the products.

CLSM (Controlled low strength material)
CLSM is a self-compacting, flowable, low-strength cementitious material used primarily as backfill, void fill and utility bedding as an alternative to compacted fill.


Conventional CLSM mixtures usually consist of water, Portland cement, fly ash or other similar products, fine or coarse aggregates or both. Fly ash obtained from thermal power plant was used.

Steps involved in backfilling in foundation
1.Before you begin the backfill process, you have to be sure that the foundation cures for at least five to seven days. There are even instances when cracks may occur when you backfill too soon.
2.The ground over which the filling has to be done should be cleaned off all grass, loose stones, rubbish of all kinds etc. If there is water in the area, it should be pumped or bailed out.
3.Determine the types of material you will use for foundation backfill. A mixture of various materials such as rocks, soil and stone are commonly used. Some soil can retain too much moisture that is not good for your foundation.
4.Try to use the refilling material from the excavated earth
5.The approved excavated material, which has been stocked, shall be cleaned of all rubbish, large size stone, vegetation etc.
6.Begin backfilling at the corners and be sure that the distribution of the soil is even so as to provide ample lateral support for the walls of your home.
7.Use an excavator to fill in twelve inches of mixed materials on the sides of the area. After which, compress the soil and stone using the rolling compactor. You must repeat the same backfill procedure until the entire area is completely filled.
8.Filling should be done in layers, each layer being of 15cm to 20cm.
9.Each layer is watered and compacted with heavy rammers of wooden logs or steel.
10.Under no circumstances black cotton soil shall be used for filling in plinth and footing pits.

The most suitable soil type for filling water logged lands (or lands with high water table) to make it stronger and stable enough to sustain foundations or sub-structures to be constructed over it is any highly draining soil like sharp sand. The common practice which is to fill with only Laterite (or red soils) then construct a concrete slab or foundation or interlocking pavers directly over it often yield in poor results; hence the reasons for the depressions that shows up at various portions on the surface of a poorly sand filled land which may consequently affect the overlying structure.

Unlike Laterite or red soil, highly draining soils like sharp sand barely retain surface and ground water, and do not behave abnormal across seasons (from dry to wet or vice-versa). For instance, because of the plastic nature of clay/red soils, they behave stable during the dry season and unstable during the wet (or rainy season).

Therefore if a foundation or floor is constructed directly over it in an area with high water table even with hardcore filling on it, it is most likely to start settling in-differentially or failing horizontally throughout its surface or longitudinal bearing and vertically downwards at various portions as we migrate from one season to another leading to visible cracks on the floor or from the foundation up to the roof after a period of time.

These cracks are often persistent and will continue to resurface until proper re-work is done. If left unattended to, it may degenerate into collapse of the structure over time. Sharp sands or suitable equivalents also perform well with changes in ground and surface temperatures in the day and at night giving the foundation or floor greater resistance in the face of extreme temperature or weather conditions.

However because of the cost implication of using sharp sand or its equivalent as the only filling material for the site, the suitable alternative practice is to first fill the land from the depth of suitable sub-soil or from the existing depth to a reasonable level with Laterite or smooth sand which is relatively cheaper before introducing sharp sand to complete the fill up to the marked out level which is often above the water table and road or drainage level.

This way, the stiffening advantage of Laterite or smooth sand combines with the merits or good qualities of sharp sand to give an acceptable degree of strength, resistance and stability.
It is instructive to note that when filling a land, precaution should be taken to ensure that the filling sand or material is well leveled and compacted to allow natural flow of surface water to the drains and to prevent excess air voids or gaps respectively in order to function to full potentials. This process can be done manually or mechanically or chemically or a combination of any of the trio depending on the nature of the project. It is better to get it right at the sub-structure level before constructing the super-structure to avoid re-works and to reduce maintenance cost in the future.

“The wise young man or wage earner of today invests his money in real estate.” Andrew Carnegie

“Every person who invests in well-selected real estate in a growing section of a prosperous community adopts the surest and safest method of becoming independent, for real estate is the basis of wealth.”
-Theodore Roosevelt

“When you invest, you are buying a day that you don’t have to work.” Aya Laraya

“Every person who invests in well-selected real estate in a growing section of a prosperous community adopts the surest and safest method of becoming independent, for real estate is the basis of wealth.”
-Theodore Roosevelt.

Land monopoly is not only monopoly, but it is by far the greatest of monopolies; it is a perpetual monopoly, and it is the mother of all other forms of monopoly.”
-Winston Churchill

“90% of all millionaires become so through owning real estate.” Andrew Carnegie

“Buy on the fringe and wait. Buy land near a growing city! Buy real estate when other people want to sell. Hold what you buy!” - John Jacob Astor, real estate and business mogul

“90% of all millionaires become so through owning real estate.” Andrew Carnegie

“When you invest, you are buying a day that you don’t have to work.” Aya Laraya

“You will come to know that what appears today to be a sacrifice will prove to be the greatest investment that you will ever make.” Gordon B. Hinkley

“When you invest, you are buying a day that you don’t have to work.” Aya Laraya

Land monopoly is not only monopoly, but it is by far the greatest of monopolies; it is a perpetual monopoly, and it is the mother of all other forms of monopoly.”
-Winston Churchill

“90% of all millionaires become so through owning real estate.” Andrew Carnegie

“You will come to know that what appears today to be a sacrifice will prove to be the greatest investment that you will ever make.” Gordon B. Hinkley

“Every person who invests in well-selected real estate in a growing section of a prosperous community adopts the surest and safest method of becoming independent, for real estate is the basis of wealth.”
-Theodore Roosevelt

“The wise young man or wage earner of today invests his money in real estate.” Andrew Carnegie

The philosophy of the rich and the poor is this: the rich invest their money and spend what is left. The poor spend their money and invest what is left.” Robert Kiyosaki

The philosophy of the rich and the poor is this: the rich invest their money and spend what is left. The poor spend their money and invest what is left.” Robert Kiyosaki