Browse Forums Renovation + Home Improvement 1 Feb 25, 2021 11:45 am Hi All, I have a 1950's double brick house on strip footing foundations in Adelaide, flat site. I'm wondering what the likelihood is for the existing strip footings being built sufficient to support a second storey without having to knock it all down and start again. Does anyone have experience with doing this? Or is the load increase from another storey going to drastically increase footing size making it unlikely? I will obviously have an engineer inspect and draw up the details I just don't want to waste the time before I gauge what costs/time I'm likely up for as it will be a much more expensive exercise if all the footings need re-doing. Beefing up the existing footings could also be an option if possible? Re: Adding a second storey to double brick with strip footin 2Mar 11, 2021 8:23 pm hey Toasty It depends on the original house construction Do you have the original house engineering details ? Also you will need to check the mortar strength used if its the old lime based mortar, then its not recommended. If you extend say a new family meals kitchen area to the side then you should be able to go Double brick and concrete suspended slab above the new extension BTW you won't be wasting your time consulting an engineer Cheers Chris Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Adding a second storey to double brick with strip footin 3Mar 12, 2021 8:41 pm Agree with Chris, a few other points; lightweight construction is usually ie no brick walls on top storey extra internal posts or steel can usually take some of the extra loads a metal roof replacing tile will save lots of weight engineer or good building design professional would help Re: Adding a second storey to double brick with strip footin 4Mar 13, 2021 11:54 am Ditto the above-a few additional ponderings as well: If your house walls are in decent condition with no serious cracking and the footings are in natural soils it’s unlikely they will need to be enlarged for a 60-70 year old house. The mechanics of it is a bit long winded but in a nutshell as the building is fairly old all the stresses and settlements within the soils under the footings are complete and the soil is ‘relaxed’ again. The existing footings can be reloaded with at least the equivalent of the existing wall loads with no dramas usually. Doesn’t work like that if the footings aren't in natural soils (and some other specific soils) but enlarging/improving existing strip footings for a single level residential addition is rare and would usually be the last resort. You will probably still need a geotech report to submit with the DA and to give to the structural engineer unless the new loads are transferred elsewhere as mentioned above but the geotech investigation/report would cost a few thousand. It would need to include depth, dimensions and ground conditions under the existing footings, so a couple hand dug holes under the existing walls are normally needed. If only to determine costs/feasibility the starting point would be to have a look around the neighbourhood to see if anyone else has added a storey in the local area and find out who did the structural design. Local knowledge is often best and a bonus if the surrounding properties are terraces/townhouses of same design. Rather than paying for a a full geotech. report, to check if its doable, dig a few holes yourself (or labourers) next to, and to the bottom of the footings and get a structural engineer to have a peek. The engineer might say that they need the geotech for detail design but they should be able to give you a good idea of what is needed. A Saturday with a shovel and a few hours for the structural engineering inspection fees is probably all you should need to pay at this stage to get a handle on the footing budget. Hi Kristy Around $1.7-1.8m or around $4,600/sqm. if you PM me your email I will send you a break up in a spreadsheet so you can get an understanding of the costs for… 1 9888 1 4521 |