Hi all,
We're in the process of building a workshop at the bottom of our garden. We were going to have an engineer help us with it all but, amidst Covid 19, our engineer stopped all communication with us, so we decided to go ahead without.
So far we've done all the groundworks which involved building three retaining walls at 1.5m high each and preparing the base for the workshop. Because our terrain is mainly clay soil, the foundations for our retaining walls are 500mm deep by 700mm wide reinforced with 10mm rebar cages. The workshop base has a footing ring at the same depth and width as the walls on the sides and an 800mm deep by 600mm wide at the front plus a 150mm deep raft with 4mm reinforced mesh on top of the ring.
We built the retaining walls with stepoc blocks reinforced with 10mm rebar horizontals on every course and vertically on every whole and infilled with concrete.
The back wall of our workshop will sit on the last retaining wall and, as mentioned before, the base is a 150mm raft sitting on 500mm d by 700mm w ring footing.
The workshop measures 7x5m externally with a flat roof which we hope to make into a green warm roof and an overhang of 1m at the front, hence our roof will be 7x6m.
We are using 4'x2' timbers for our stud walls and 9'x3' for our roof joists.
We've had some help from some friends who have built similar things and were feeling quite confident until we started trying to figure out the size of the timbers for our door lintels.
We want to have 3m bifold door and a single door next to it at the front of the building, but this obviously leaves very few studs taking the weight of the roof at the front. We planned for two 8'x2' bolted together, but are now unsure if that would be enough.
According to our calculations, our roof will weigh about 5400 kg; this includes joists, 2 layers of OSB, EPDM, insulation, 2 rooflights and an 80mm extensive green roof.
Your thoughts on the lintel above the doors would be much appreciated.
We're in the process of building a workshop at the bottom of our garden. We were going to have an engineer help us with it all but, amidst Covid 19, our engineer stopped all communication with us, so we decided to go ahead without.
So far we've done all the groundworks which involved building three retaining walls at 1.5m high each and preparing the base for the workshop. Because our terrain is mainly clay soil, the foundations for our retaining walls are 500mm deep by 700mm wide reinforced with 10mm rebar cages. The workshop base has a footing ring at the same depth and width as the walls on the sides and an 800mm deep by 600mm wide at the front plus a 150mm deep raft with 4mm reinforced mesh on top of the ring.
We built the retaining walls with stepoc blocks reinforced with 10mm rebar horizontals on every course and vertically on every whole and infilled with concrete.
The back wall of our workshop will sit on the last retaining wall and, as mentioned before, the base is a 150mm raft sitting on 500mm d by 700mm w ring footing.
The workshop measures 7x5m externally with a flat roof which we hope to make into a green warm roof and an overhang of 1m at the front, hence our roof will be 7x6m.
We are using 4'x2' timbers for our stud walls and 9'x3' for our roof joists.
We've had some help from some friends who have built similar things and were feeling quite confident until we started trying to figure out the size of the timbers for our door lintels.
We want to have 3m bifold door and a single door next to it at the front of the building, but this obviously leaves very few studs taking the weight of the roof at the front. We planned for two 8'x2' bolted together, but are now unsure if that would be enough.
According to our calculations, our roof will weigh about 5400 kg; this includes joists, 2 layers of OSB, EPDM, insulation, 2 rooflights and an 80mm extensive green roof.
Your thoughts on the lintel above the doors would be much appreciated.
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