Question about stumps

[Strannik]

Wonder if anyone here would know.

I have a house which sits on a slope on concrete stumps.

Question: when they put the stumps in do they have the same length, or they can be of different length?

The reason for asking is that on one side of the house there is enough headroom to walk under the house, whereas on the other it's about a meter off the ground, so i was thinking to dig out some earth to make it level.

Will this be possible, or will the stumps be shorter on one side?

 

[battler]

They are probably shorter, but could be replaced with longer ones if it was excavated.

 

[Strannik]

that would suck

also another question
if i was to raise this house, since it's on a downward slope towards the back end would i be able to raise it to full height at the front end, meaning the rear end would be much higher off the ground? or will I need to do excavation on the front end?

if i could just raise it off the front end, than i'd probably be able to make it 2.5 stories high

 

[battler]

I think it would probably be worth getting a professional on site to advise what can be done and an idea of cost.

 

[vbplease]

The reason for asking is that on one side of the house there is enough headroom to walk under the house, whereas on the other it's about a meter off the ground, so i was thinking to dig out some earth to make it level.

Will this be possible, or will the stumps be shorter on one side?

it's very likely that the stumps are shorter on the higher side, as they are designed for particular embedment length. So definitely don't dig into the earth and risk underpinning them.

if i was to raise this house, since it's on a downward slope towards the back end would i be able to raise it to full height at the front end, meaning the rear end would be much higher off the ground?

Yes, anythings possible Steel posts with rod bracing is the more conventional method rather than new concrete stumps.. I was actually driving through Paddington today and saw a house raised on a very steep slope - legal height on the short side and about about twice the height on the high side braced accordingly though

 

[Strannik]

yeah definitely won't be putting in new concrete stumps, they are hard to build around

i guess i might get a professional in to tell me what can be done and to quote on it at the same time so i know how much to take when i go to rob a bank

 

[Perp]

Don't forget that you may need Council approval to raise it - particularly if heritage listed.

 

[wylie]

Regarding your question about the raising issue...... my understanding is that the house can go to 8.5m from the natural ground level in a certain year (not sure what year).

That means that if the land slopes you may find the section of house that is already pretty high will cause a problem if raising the whole house takes it over 8.5m. In our case, we could add a second story to the back section of our house which is on the ground but could not add another storey over the whole roof area because the front of our house is already two storey. Even though we dug out our front yard to help create the second story, we were told that the 8.5m measure is taken from the "natural" ground level, ie. the part of our yard that we didn't dig out.

So, we were told we could probably make three storeys in part of our house as long as the height from the original ground level is not more than 8.5m. Obviously plenty of houses in Paddington are higher than this, and have been for nearly 100 years, so I am not sure what would happen if someone wanted to raise a house in a very hilly place now.

This is definitely worth making sure you get right or you could have a real problem with council and/or neighbours.

This has created a furore in Holland Park West where a house rises to 11.5m (front page Sunday's paper). According to the paper the BCC has allowed this (unbelievable!!!) but in Camp Hill there is a house that looks very strange that the owners were forced to leave the top floor off due to the height restrictions.

And another on Old Cleveland Road at Camp Hill that has come to a standstill and I wonder if it is because it appears to be well over 8.5m.

 

[Strannik]

well the slope goes from right front corner (if facing a house) down to far left

so it will be interesting exercise if I decide to go that way.

The initial question though was more about digging around so i can create more level surface and can walk under it, maybe put a concrete floor so i can store stuff there.

 

[battler]

The initial question though was more about digging around so i can create more level surface and can walk under it, maybe put a concrete floor so i can store stuff there.

You may be able to dig out to the level you want, in between the existing stumps, then replace stumps to new level, and then remove the old ones.

You may also be able to put a structural beam in place spanning a larger distance, creating a more usable flat area.

 

[Savanna100]

I agree with Battler above, you should engage a structural engineer, they will know exactly what to do. I dont suggest raising the house, its probably much easier to dig out and put new load bearing structure under the currently short end of the house. Be guided by your engineer but before you spend money on an engineer go along and have a talk to the Council planner for free first, they will set you straight on the height issue, trust me once that is resolved, then engage your engineer.

 

[Strannik]

how deep do the stumps usually go?

 

[battler]

Stump depth is determined by a soil test indicating that the ground, at a certain depth, will support the weight. This will vary in different areas. You may be able to get this information from council.

 

[enricofermi]

Concrete stumps are a great idea.....our wooden stumped houses get continually eaten by termites. Restumping is a costly exercise.

 

[wylie]

I have been told by a stumper that treated wooden stumps will last as long as concrete stumps. At least with stumped houses you can SEE the mud trails. Of course the little blighters CAN be inside a timber stump but a regular check will soon suss this out.

I have actually seen plenty of "exploded" concrete stumps.

Either concrete OR timber stumps just need regular checks. A timber stump can be "drilled" with poison whereas a concrete stump must be "encircled" at the base with poison. Both are simple termite treatments and/or prevention.

 

[Strannik]

well, both concrete and wooden stumps are about the same size, so from aesthetic point of view it doesn't make a difference. Steel stumps are the go

 

[wylie]

Interestingly, I reckon timber stumps are much more aesthetically pleasing, and when we restump, if we are restumping a timber stumped house, we opt for timber again. I don't like concrete stumps at all on an old queenslander.

Of course, many old places have had timber stumps replaced by concrete so we make a call on each one. If the queensland is "original" we replace with timber, so it keeps its original look.

We have two houses that one day we will probably raise and restump. Both have a mixture of timber and steel stumps now, but if we raise them, we will probably use steel and install some large beams to give large areas without stumps, because we would more than likely build down into the lower area and double the living space. Of course, doing this takes away the unique "queenslander on stilts" looks anyway.

 

[Perp]

Interestingly, I reckon timber stumps are much more aesthetically pleasing, and when we restump, if we are restumping a timber stumped house, we opt for timber again. I don't like concrete stumps at all on an old queenslander.

Me, too! I think you go either timber, and preserve the look, or go for steel if you're hiding them away in cavities anyway.

 

[gecho1]

stumps

Stranick, your stumps have to go to natural ground. This means that every stump or pier has to reach clay. The depth of the holes can change from stump to stump.
Your first step is to engage the services of an engineer to take core samples of the ground. This will give you an indication of what you can do.
As for the 8.5m limit, this is taken from a median point. A surveyor can take your RL's and detrmine the height of your natural ground level. From here you can guage whether you have the height to go up.



FYI- Recently did a home in Bulimba SEQ, with a concrete slab. However due to the site classification we had to put piers in o support slab. Depth of piers-30m
yes 30 metres deep- cost of project-you don't want to know

Hope this helps you out


Adrien Mamet
www.mametconstructions.com.au