Tallinn's #1 terrace builder
Terrassiehitus Tallinn: Screw pile installation
Terrassiehitus Tallinn installs screw piles for terraces, extensions and garden houses across Tallinn and Harju County. They are our standard terrace foundation: hot-dip galvanised steel piles are driven mechanically without excavation or concrete curing, so beams can be fitted to the pile heads the same day.
Our standard pile is 1.5 m long and 76 mm in diameter, placing its helix below our estimated 1.2 m frost depth in Harju County. The zinc coating is 80 microns thick. We install each pile using a torque meter and record the reading individually.
- Licensed and insured
- 100% satisfaction guarantee
- 537 test piles; 1,127 piles extended
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When are screw piles the right foundation?
A hand auger hits stones before pile depth
Screw piles suit sites where a hand auger reaches 1.5 m through sand, clay or till without meeting bedrock. Where limestone stops the auger at 30 cm, we build a block foundation on crushed stone instead.
An old terrace has sunk at one corner
If decking tilts by more than 1 cm per metre, a ground-level block may have moved with frost or a timber post may have rotted. We install a replacement pile 30 cm from the old post rather than in its loose backfilled hole.
Groundwater rises in spring
If a spring test hole fills with water down to 1 m, excavation for a block foundation would flood and leave the crushed-stone bed wet. A screw pile can be installed in the wet ground without pumping it dry; its bearing capacity is assessed from the torque reached in that soil.
Why Torque Indicates Pile Bearing Capacity
The steel helix cuts into the ground like a screw into timber. Denser soil resists turning and later resists the pile sinking under load. For a 76 mm pile, a final torque of 1,000 Nm corresponds to an ultimate bearing capacity of 28 kN.
Ice lenses in clay and till can lift the frozen surface and grip a pile shaft. The helix below the estimated 1.2 m frost depth resists that uplift, so we do not shorten a 1.5 m pile even if it reaches target torque sooner.
How the Installation of Screw Piles Works
Test holes and pile layout
We use a hand auger to make test holes at two opposite corners, then draw the pile plan. A 24 m² terrace has three main beams 1.5 m apart, each supported by four piles at 2 m intervals: 12 piles in total. We mark the positions with string and paint and check the diagonals for square.
Installation and torque records
One worker runs the pile driver at a steady speed while another keeps the pile plumb until the torque meter reads 1,000 Nm. We record each pile's number, depth and final torque. In loose sand or fill, a pile that has not reached the target at 1.5 m receives a 1 m extension and goes down to 2.5 m.
Trimming pile heads and fitting beam seats
We laser-level the pile heads, cut them to height and coat the exposed edges with zinc paint. Each U-shaped beam seat is secured with two hot-dip galvanised M12 bolts. We check every head height before lifting the beams into place.
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- Licensed and insured
- 100% satisfaction guarantee
Harju County Sand, Clay and Limestone
Ground conditions vary across Tallinn and Harju County. Piles turn readily in the sand of Nõmme, Pirita and Viimsi but torque rises slowly; it rises faster in Saue and Keila clay, while shallow limestone can stop a pile before frost depth. We install the first pile on each site as a test and use its final torque to choose the length of the rest. By the end of 2025, we had installed 537 test piles and extended 1,127 piles by 1 m, including 612 in Rae Parish fill and 389 in Viimsi sand.
Screw pile installation: price and time
Screw pile installation starts at €55 per pile: from €660 for 12 piles beneath a 24 m² terrace or €1,100 for 20 piles. A 1 m extension for loose sand or fill adds €47 per pile. Two workers install a 12-pile foundation in one working day, from morning test holes and layout to installation, records and trimmed pile heads. Twenty piles take two working days. Our average foundation uses 14.6 piles. Site surveys and quotes are free in Tallinn and Harju County; travel beyond the county costs €0.87 per kilometre.
Screw piles for a garden house near Saue
Owner: Hannes E., self-build garden house. Plot: Near the Saue post station, Jõgisoo, Saue parish. Job number: 1 471.
1. Test holes and pile plan: hand-auger holes at opposite corners of the 4 × 5 m garden house showed clay. The plan set out three beams 2.5 m apart, each supported by three piles at 2 m intervals: nine piles in total.
2. Installation and torque record: eight piles reached 1,000 Nm on the first attempt. The ninth met rock at 1.1 m, so we removed it and reinstalled it 30 cm along the same beam line, shifting the beam seat accordingly. We recorded every pile's number, depth and final torque.
3. Pile heads and beam seats: we laser-levelled the heads, treated the cut edges with zinc paint and fitted a U-shaped beam seat to each with two hot-dip galvanised M12 bolts.
Construction price: installation of screw piles 9 piles × €55 = €495, the amount includes 24% VAT.
Construction time: 1 working day for two men at the end of April 2026, including turning the pile that ran into the rock.
Finished foundation: All 9 piles have a final torque of 1000 Nm in the protocol and the pile heads are at the same height.
Frequently Asked Questions
How many screw piles does a 32 m² terrace need?
A 32 m² terrace uses 15 piles: five beneath each of three main beams, spaced 2 m apart, with beams 1.5 m apart. At €55 per pile, the foundation starts at €825. Our crews installed 604 piles in 2023, 617 in 2024 and 629 in 2025.
What happens if a pile hits rock?
If one pile hits rock before 1.5 m, we remove it and reinstall it 30 cm along the same beam line, moving the beam seat with it. If repeated obstructions reveal a limestone layer, we use blocks on a crushed-stone base for the remaining foundation.
Do screw piles rust in the ground?
The 80-micron hot-dip galvanised coating protects the steel from soil moisture. Zinc wears fastest at ground level where air and moisture meet, so we leave pile heads 10 cm above ground and coat any cut or scratched areas with zinc paint.
Can a high terrace be built on screw piles?
We use screw piles for terraces whose decking is no more than 1 m above ground. Higher terraces and shelters use post foundations because wind creates sideways force at the supports that one pile cannot resist.
Get in touch
Call +372 XXXX XXXX to arrange a test hole and pile plan. We can also visit on weekday evenings until 19:00.