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We have installed 6 dry wells around the building as there was no empty space for drainage water.

We did this as per the engineer's advice.

Sand texture:

  • It's clay
  • Water table 2 ( During rainy season ) to 4 feet ( During summer )
  • Ground water is saline

I asked my engineer if it will impact ( Differential Settlement ) the building foundation he said it's not a problem as all the buildings in the town are standing in wet ground ( 5 feet ground water table ).

But I'm worried about the building foundation such as

  • Capillary effect
  • Hydrostatic pressure on walls
  • Water seepage on the walls
  • Differential settlement

Four 2 feet by 2 feet dry wells on one side of building

Two 3 feet by 3 feet dry wells on the other of building

What should I do ?

  • Should I keep plants around the building wall and dry well ?
  • What kind of Plant's root would not damage the wall ?

Here is the photo of sample retaining wall that builder has in mind. Any suggestions are welcome

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Here is how the dry wells ( 5 feet depth ) are going to be connected sequentially

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I'm happy with the whole but I'm worried about my building foundation like I mentioned earlier and I want to take all the steps to make sure my building is safe and sound.

Update:

Our house is built like in the below picture [ Framed structure not Load bearing wall structure ]

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Sand Character:

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Update

  • Please find the video of dry wells on the south side of the building here

  • Please find the video of dry wells on the north side of the building here

FYI:

According to local engineers , I have nothing to worry about this whole cement ring well drainage set up , because ground water table level is already at 3 to 5 feet so every building in the town is practically standing at wet ground so this drainage well will not do any harm. But I'm not convinced this dry well can saturate the soil bit more and could cause settlement which can lead to fraction in the wall ?

Somebody please give their wisdom in this.

Amogam
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  • If you are lucky then the builders have sealed the foundation well. Trees are bad if too close(your situation), grass and flowers good. This site might help with what to plant, knowing the ground water. https://gardening.stackexchange.com/ – crip659 Jul 11 '22 at 21:15
  • Builder mentions the foundation is sealed with Black paint or tar bitumen so nothing can penetrate the wall. he also mentions he has built building close by water bodies and nothing happened. the reason he mentions is that the ground water table is high like 5 feet so literally all the buildings are standing in wet clay ground so no problem. What's your take on this ? – Amogam Jul 11 '22 at 21:22
  • If they are good local builders, they should know how to do it right. It costs them money to fix mistakes, when the basement gets flooded. Your older neighbours should know if they do it right. – crip659 Jul 11 '22 at 21:26
  • Just want to be bit careful and make right scientific decision than completely trusting them and as per the agreement any xtra work cost money for the owner only not the builder. – Amogam Jul 11 '22 at 21:30
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    The engineer had you position the dry wells adjacent to the foundation? I hope your foundation is a slab I can’t tell. This is really an engineering question and the type of foundation and the actual soil compression/ drainage factors would need to be known. – Ed Beal Jul 11 '22 at 21:37
  • It's 6 feet deep pad footing and load bearing structure foundation. He placed the dry well which is 1.5 metre deep but 3 feet away from each column. – Amogam Jul 11 '22 at 21:45
  • Extra work(building an addition) is on the owner, but the builder should warranty the foundation from leaks for a number of years. Your neighbours who use the same builder will not lie if he is not good. – crip659 Jul 11 '22 at 21:45
  • @crip659 - He has no bad reputation but I just want to be taking some extra precautious steps in scientific way. I'm worried as my life savings has gone into this building. – Amogam Jul 11 '22 at 21:48
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    You've paid an engineer familiar with your local area and have gotten input and advice from him, but you don't trust it so you're turning to a bunch of strangers on the internet who don't even know what part of the world you live in? That's... interesting. If you're that worried, spend a bit more money and ask another local engineering firm to review the plans. If there are issues, it was money well spent, if there aren't then the peace of mind should make it money well spent. – FreeMan Jul 12 '22 at 16:03
  • @FreeMan - I consulted with one more engineering company and they also mentioned it's not a problem. But as far as my general knowledge goes "Stagnation of water around the building should be avoided ". But what I feel , if there's anything I can do to cover all the possible scenarios , it'd be great. A stitch in time saves nine :) – Amogam Jul 12 '22 at 20:04
  • @FreeMan - probably Mumbai, by the profile. – Tim May 09 '23 at 10:44

1 Answers1

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Answer is PLINTH PROTECTION for the plinth beam.

Plinth beam is meant to protect the building from Differential settlement and distribute the dead and live load of the building.

It also stops the capillary action so water damage won't be done.

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Add Plinth Protection Layer adjacent to Plinth ( Use just PCC[Plain Concrete Cement] ) for 1 metre so it stops the water from coming in touch with plinth wall this stops capilary action.

If water percolates and damages the foundation and differential settlement starts then this Plinth protection will stop the continuation of cracks in Plinth wall.

Update:

But you may wait and see how the building settles and if any crack appears then go for FOUNDATION UNDERPINING

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enter image description here

Amu
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    In the Pacific Northwest we call that a side walk. Sorry could not help saying that but it helps prevent damage on several levels as you mentioned. – Ed Beal Jul 12 '22 at 16:01
  • But I have got 6 dry wells around the building , how am I supposed to do ? Should I leave the dry wells opening and cover the rest of the area with PlNTH protection ? – Amogam Jul 12 '22 at 20:06
  • Not sure ,But check out my updated answer it might help you – Amu Jul 12 '22 at 20:13
  • @Amu - My foundation has Concrete RCC column and RCC footer. Even if water percolates into the ground .. can water damage the RCC .. as far as I know water can damage walls with bricks and not RCC or PCC or DPC. So percolation of water .. can it really affect the foundation ? – Amogam Jul 12 '22 at 21:15
  • I'm not sure again but what I know is if you soil is Expansive clay . it can shirnk and expand depending upon the weather and this can cause swelling and damage ..it'd be a good idea to have Sloped Plinth Protection around the house ( PCC ) and keep the soil under same level of moisture from all sides so Differential settlement can be avoided. – Amu Jul 12 '22 at 21:46
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    Oh my god all this increases my anxiety.. my ground is full of clay , I'm confused on what to do ... because drywell's are already installed.. even if I do Plinth protection what about the areas that are having dry well ... should I take out the dry wells ? if I take out what can I do about the drainage water ? Feels like I gave the whole project to bunch of idiots and my peace of mind is gone... desperately looking to do something to save my building foundation and do something about the drainage as well – Amogam Jul 13 '22 at 09:50
  • Here is my take , if your foundation is completely plastered without leaving single brick then you need not to worry. Because bricks can absorb water from the drain through capillary action and it'll weaken the wall and slowly lead to weakening of structure then you definitely have to worry in addition to that plastered foundation wall will not let the water in – Amu Aug 22 '22 at 14:38
  • My recommendation is do not plant any trees,plants or bushes with tap roots within 10 feet distance from the building. Tap roots can tamper the building foundation wall or concrete. In the case of wall .. damage in the wall can cause brick to come in contact with water and that's not good.. in the same way if concrete gets tampered then bar inside it will start the corrosion and it'll loose all the strength slowly. – Amu Aug 22 '22 at 14:43
  • Coat the foundation with water proof paint other than Tar so you need not to worry about plaster coming into contact in the very first place. – Amu Aug 22 '22 at 14:44
  • I've seen building getting transported from one place to another place by jockeying the foundation and moving it with rail kind of structure. so do not worry about the dry well any more .. make sure foundation is plastered and it has tar and other water proof coating and also make sure trees with tap roots are planted far away – Amu Aug 22 '22 at 14:47
  • My foundation is completely plastered and tar also has been applied already. But there's no other water proof coating is done. – Amogam Aug 22 '22 at 19:35
  • I'm bit concerned that these dry wells will oversaturate the clay beneath and soften the earth which in turn might cause the building settle differently and cause fractures in wall. Hope you understand my point – Amogam Aug 22 '22 at 19:36
  • Here is a video of guy moving his house 500 metres from his own place (https://youtu.be/0SwWIY1ZXAU ) – Amu Aug 22 '22 at 19:59
  • Good to know that you have plastered all the bricks in foundation and tar's applied too. If you have built your house with quality cement,sand(no salt) and proper strong steel bar for concrete then you have nothing to worry just keep in mind about the tree plantation distance so it doesn't fracture the foundation and cause any weakness if possible apply water resistant coat then you are good IMO. Don't worry about Soil over saturation or earth softening , remember the whole weight of the building will be equally transferred to all the pillars – Amu Aug 22 '22 at 20:05