The history is that a brickie lived here years ago and some things he did were not ideal, but now we want to alter several openings.
This is a 1950s 3 bed semi, 50mm cavity brick walls, 330mm thickness of external walls + cavity + plaster.
1. We might want to replace a pair of concrete lintels supporting outside wall above a 1500mm opening to existing extension. For one thing the opening could benefit slight widening (square the angled opening) and heightening to let more light in, for another the lintels are supported by perhaps only 4 inches, and, on one side, the opening is on an angle - it widens ... I have yet to inspect the overlap on the wider side and fear <100mm.
Currently there are 2no. 8" (depth) existing concrete lintels that do not bridge the cavity.
The opening is 1500mm, but could grow to 1600mm.
Looking at steel insulated cavity lintels, I see 3 typical categories: standard, heavy duty, and extra heavy duty.
e.g. http://www.buildingsteel.co.uk/IG_lintel_selection_chart.htm
Is there any rule of thumb that indicates which strength is appropriate in the modest situation described? The catnic equivalent?
The online tools for calculating required strength leave me cold.
The second opening of interest is 2400mm where we might remove old sliding doors that curiously separate lounge from existing extension. we need to build the wall out on one side (no impact on existing lintels) but could benefit from widening opening on other side by 100mm (it would remove nib between original lounge and existing extension which itself was built well within party wall, thus giving cleaner lines to a more open plan room), and raising the opening to let more natural light in.
If altering the opening but not widening it overall, I assume that I still need BC, but what steel lintel for that width?
Alternatively, to fit with different approach, what glulam size is indicated?
Finally, there is an internal lintel/beam in a single block supporting wall, where the lounge and dining rooms were originally separate. It looks ugly and would benefit from either reducing the nib on one side, and/or, raising the height of the opening (which is currently an odd 2350mm wide, 6' high archway when it really wants to be either ceiling height, or at least have more clearance.
I ponder whether a glulam beam would add architectural interest and/or the beauty of natural timber.
The existing plastered wall is 135mm, and the max opening would be 2550mm.
Any idea what glulam size would be indicated, and with what overlap? I know that local BC suggested a steel beam of 180mm for someone up the road, when his builder had fitted 150mm, but eventually signed off the work.
Any idea how to minimise the BC costs of our efforts?!
This is a 1950s 3 bed semi, 50mm cavity brick walls, 330mm thickness of external walls + cavity + plaster.
1. We might want to replace a pair of concrete lintels supporting outside wall above a 1500mm opening to existing extension. For one thing the opening could benefit slight widening (square the angled opening) and heightening to let more light in, for another the lintels are supported by perhaps only 4 inches, and, on one side, the opening is on an angle - it widens ... I have yet to inspect the overlap on the wider side and fear <100mm.
Currently there are 2no. 8" (depth) existing concrete lintels that do not bridge the cavity.
The opening is 1500mm, but could grow to 1600mm.
Looking at steel insulated cavity lintels, I see 3 typical categories: standard, heavy duty, and extra heavy duty.
e.g. http://www.buildingsteel.co.uk/IG_lintel_selection_chart.htm
Is there any rule of thumb that indicates which strength is appropriate in the modest situation described? The catnic equivalent?
The online tools for calculating required strength leave me cold.
The second opening of interest is 2400mm where we might remove old sliding doors that curiously separate lounge from existing extension. we need to build the wall out on one side (no impact on existing lintels) but could benefit from widening opening on other side by 100mm (it would remove nib between original lounge and existing extension which itself was built well within party wall, thus giving cleaner lines to a more open plan room), and raising the opening to let more natural light in.
If altering the opening but not widening it overall, I assume that I still need BC, but what steel lintel for that width?
Alternatively, to fit with different approach, what glulam size is indicated?
Finally, there is an internal lintel/beam in a single block supporting wall, where the lounge and dining rooms were originally separate. It looks ugly and would benefit from either reducing the nib on one side, and/or, raising the height of the opening (which is currently an odd 2350mm wide, 6' high archway when it really wants to be either ceiling height, or at least have more clearance.
I ponder whether a glulam beam would add architectural interest and/or the beauty of natural timber.
The existing plastered wall is 135mm, and the max opening would be 2550mm.
Any idea what glulam size would be indicated, and with what overlap? I know that local BC suggested a steel beam of 180mm for someone up the road, when his builder had fitted 150mm, but eventually signed off the work.
Any idea how to minimise the BC costs of our efforts?!
